Java 既然Handler（）已不推荐使用，我该使用什么？

如何修复此代码中的弃用警告？或者，是否有其他方法可供选择

Handler().postDelayed({
    context?.let {
        //code
    }
}, 3000)

---

有关更多信息，请使用Executor而不是handler。
要实现延迟后处理，请使用ScheduledExecutorService：

ScheduledExecutorService worker = Executors.newSingleThreadScheduledExecutor();
Runnable runnable = () -> {
    public void run() {
        // Do something
    }
};
worker.schedule(runnable, 2000, TimeUnit.MILLISECONDS);

---

考虑使用协同程序

scope.launch {
    delay(3000L)
    // do stuff
}

---

不推荐使用的函数是处理程序的构造函数。根据文档（）使用

处理程序（Looper.myLooper（））.postDelayed（runnable，delay）

， “在处理程序构造过程中隐式选择一个循环器可能会导致错误，操作会自动丢失（如果处理程序不期望新任务并退出），崩溃（如果处理程序有时是在线程上创建的，而没有活动的循环器），或竞争条件，其中处理程序关联的线程不是作者预期的。相反，请使用执行器或显式指定循环器，使用循环器#getMainLooper、{link android.view.view#getHandler}或类似工具。如果为了兼容性需要隐式线程本地行为，请使用新的处理程序（Looper.myLooper（））让读者明白。”

---

我们应该停止使用没有循环器的构造函数，而是指定一个循环器。

如果您想避免Kotlin（

？

或

！！

）中的空检查，您可以使用

Looper.getMainLooper（）

，如果您的

处理程序正在处理一些与UI相关的事情，例如：

Handler(Looper.getMainLooper()).postDelayed({
   Toast.makeText(this@MainActivity, "LOOPER", Toast.LENGTH_SHORT).show()
}, 3000)

注意：使用
requireContext（）
而不是
this@MainActivity
如果您使用的是片段。
请使用此

 lifecycleScope.launch {
     delay(2000)
     // Do your stuff
 }

Looper.myLooper（）？.let{
处理程序（it）.postDelayed({
//你的代码
},2500)
}
例如，当从头开始创建全屏活动时，Android Studio 4.0.1会生成handler（）etc代码。我知道有人鼓励我们使用Kotlin，我也是这样做的，但有时我会使用示例项目来获得想法。
似乎很奇怪，当AS实际生成代码时，我们会受到AS的惩罚。检查错误并修复它们可能是一项有用的学术活动，但也可能为我们的爱好者生成新的干净代码……
只有无参数构造函数不受欢迎，现在最好通过
Looper.getMainLooper（）
方法在构造函数中指定
Looper

将其用于Java
把它用在Kotlin身上
在处理程序构造函数中提供一个循环器

Handler(Looper.getMainLooper())

使用生命周期范围更容易。内部活动或片段

 lifecycleScope.launch {
     delay(2000)
     // Do your stuff
 }

或者使用处理器

        Handler(Looper.myLooper()!!)

Java回答

我写了一个简单易用的方法。您可以在项目中直接使用此方法。delayTimeMillis可以是2000，这意味着此代码将在2秒后运行

private void runJobWithDelay(int delayTimeMillis){
    new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
        @Override
        public void run() {
            //todo: you can call your method what you want.
        }
    }, delayTimeMillis);
}

从API级别30开始，有2个构造函数被弃用







谷歌在下面解释了原因

在执行过程中隐式选择活套
处理程序构造可能会导致错误，其中操作是静默的
丢失（如果处理程序不需要新任务并退出），则崩溃
（如果有时在没有循环器的线程上创建处理程序
活动）或争用条件，其中线程与处理程序关联
这不是作者所期望的。相反，请使用执行人或
使用Looper#getMainLooper，{link显式指定循环器
android.view.view#getHandler}或类似。如果隐式线程
本地行为是兼容性所必需的，请使用新
处理程序（Looper.myLooper（），callback），以使读者明白

解决方案1:使用

1。在主线程中执行代码

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

2.在后台线程中执行代码

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

注意：请记住使用后关闭执行器

backgroundExecutor.shutdown(); // or backgroundExecutor.shutdownNow();

handlerThread.quit(); // or handlerThread.quitSafely();

3.在后台线程中执行代码，并在主线程上更新UI

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

解决方案2:使用以下构造函数之一显式指定循环器







1。在主线程中执行代码

1.1.带活套的处理器

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

1.2带活套和处理程序的处理程序。回调

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

2.在后台线程中执行代码

2.1.带活套的处理器

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

2.2.带活套和处理程序的处理程序。回调

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

注意：请记住在使用后释放螺纹

backgroundExecutor.shutdown(); // or backgroundExecutor.shutdownNow();

handlerThread.quit(); // or handlerThread.quitSafely();

3.在后台线程中执行代码，并在主线程上更新UI

Java

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Execute a task in the main thread
mainExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // You code logic goes here.
    }
});

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
    }
});

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here
    }
}, 3, TimeUnit.SECONDS);

// Create an executor that executes tasks in the main thread. 
Executor mainExecutor = ContextCompat.getMainExecutor(this);

// Create an executor that executes tasks in a background thread.
ScheduledExecutorService backgroundExecutor = Executors.newSingleThreadScheduledExecutor();

// Execute a task in the background thread.
backgroundExecutor.execute(new Runnable() {
    @Override
    public void run() {
        // Your code logic goes here.
        
        // Update UI on the main thread
        mainExecutor.execute(new Runnable() {
            @Override
            public void run() {
                // You code logic goes here.
            }
        });
    }
});

Handler mainHandler = new Handler(Looper.getMainLooper());

Handler mainHandler = new Handler(Looper.getMainLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute tasks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper()); 

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute taks in the background thread.
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        return true;
    }
});

// Create a handler to execute code in the main thread
Handler mainHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a Looper
HandlerThread handlerThread = new HandlerThread("HandlerThread");
handlerThread.start();

// Create a handler to execute in the background thread
Handler backgroundHandler = new Handler(handlerThread.getLooper(), new Handler.Callback() {
    @Override
    public boolean handleMessage(@NonNull Message message) {
        // Your code logic goes here.
        
        // Update UI on the main thread.
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                
            }
        });
        
        return true;
    }
});

Kotlin

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

我通常用这个

代码：

截图：

如果您使用变量作为Handler和Runnable，请像这样使用它

private Handler handler;
private Runnable runnable;

handler = new Handler(Looper.getMainLooper());
    handler.postDelayed(runnable = () -> {
        // Do delayed stuff here
         handler.postDelayed(runnable, 1000);
    }, delay);

您还需要删除onDestroy（）中的回调

科特林合作计划

// Create an executor that executes tasks in the main thread.
val mainExecutor = ContextCompat.getMainExecutor(this)

// Execute a task in the main thread
mainExecutor.execute {
    // You code logic goes here.
}

// Create an executor that executes tasks in a background thread.
val backgroundExecutor: ScheduledExecutorService = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.
}

// Execute a task in the background thread after 3 seconds.
backgroundExecutor.schedule({
    // Your code logic goes here
}, 3, TimeUnit.SECONDS)

// Create an executor that executes tasks in the main thread. 
val mainExecutor: Executor = ContextCompat.getMainExecutor(this)

// Create an executor that executes tasks in a background thread.
val backgroundExecutor = Executors.newSingleThreadScheduledExecutor()

// Execute a task in the background thread.
backgroundExecutor.execute {
    // Your code logic goes here.

    // Update UI on the main thread
    mainExecutor.execute {
        // You code logic goes here.
    }
}

val mainHandler = Handler(Looper.getMainLooper())

val mainHandler = Handler(Looper.getMainLooper(), Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute tasks in the background thread.
val backgroundHandler = Handler(handlerThread.looper)

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()


// Create a handler to execute taks in the background thread.
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.
    true
})

// Create a handler to execute code in the main thread
val mainHandler = Handler(Looper.getMainLooper())

// Create a background thread that has a Looper
val handlerThread = HandlerThread("HandlerThread")
handlerThread.start()

// Create a handler to execute in the background thread
val backgroundHandler = Handler(handlerThread.looper, Handler.Callback {
    // Your code logic goes here.

    // Update UI on the main thread.
    mainHandler.post {
        
    }
    true
})

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

在Kotlin中使用此结构是个好主意

companion object Run {
   fun after(delay: Long, process: () -> Unit) {
      Handler(Looper.getMainLooper()).postDelayed({
          process()
      }, delay)
   }
}

后称为

Run.after(SPLASH_TIME_OUT) {
   val action = SplashFragmentDirections.actionSplashFragmentToLogin()
   v.findNavController().navigate(action)
}

这在Kotlin中不起作用，因为
Looper.myLooper（）
返回一个
Looper？
（可能为空值）。@EllenSpertus然后添加一个空检查，或使用Looper.myLooper（）！！如果NPE为空，将抛出NPE。如果你在一个带有循环器的线程上，它将返回非null。如果不是，它将返回null，并应在任何语言中引发异常。事实上，这是一个不错的答案。在
活动
或
片段
：
lifecycleScope.launch{delay（3000L）}
中，这真是太棒了！啦啦队成功了。谢谢