Java 检查外部活动是否已成功打开？

如何检查设置中的外部活动是否已成功打开？在这种情况下，我想检查

设置。操作\u位置\u源\u设置

是否成功打开

这是我的密码：

Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);                    
startActivity(intent);

---

也许，您可以使用一些

布尔值

标志变量来检查我们是否应该侦听当前

活动

的

onPause（）

生命周期事件。 然后，我们可以在

onPause（）

中检查该标志变量的值。如果为真，则更有可能调用它，因为下一个

活动

已成功打开。示例

活动

可能如下所示：

public class MainActivity extends AppCompatActivity {

    // a boolean variable to check whether or not another activity is opened or not
    // if opened our this activity will be paused
    private boolean externalActivityOpened = false;

    // a boolean variable to filter all other condition due to which our activity
    // can be paused
    private boolean startLookingIfCurrentActivityIsPaused = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        openLocationSettings();
    }

    private void openLocationSettings() {
        Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
        // set variable to true...if activity is paused now, there is high chance
        // that it is paused because the location settings has been opened
        startLookingIfCurrentActivityIsPaused = true;
        // this solution will fail if at this very point the interruption occurs such as a phone call
        // other than that it should work fine I guess xD
        startActivity(intent);
    }

    @Override
    protected void onPause() {
        super.onPause();
        // we check to see if onpause is called after we wanted to start the location settings
        // if yes then it is almost certain that the new activity has been started
        if (startLookingIfCurrentActivityIsPaused) {
            externalActivityOpened = true;
            startLookingIfCurrentActivityIsPaused = false;
            Toast.makeText(this, "New activity has been started!", Toast.LENGTH_LONG).show();
        }
    }
}

---

有类似于

startActivityForResult

Yes的内容，但是如何在我的案例中使用它呢？您可以向

Activity

lifecycle寻求帮助。如果成功打开另一个

活动

，则将调用第一个活动中的

onPause（）

。@cgb\u pandey您能给我一个cas实现作为答案吗？我已添加答案。不过这只是一个解决办法。有时活动存在，但由于某种原因它根本无法打开。这在华为的一些设备中发生。我已经测试过你的代码了。很遗憾，您的代码没有解决这个问题。在这种情况下，对

startActivity（）

的调用是否会引发

ActivityNotFoundException

？您在日志中看到了什么吗？我的用户没有遇到任何崩溃，因此可能不是ActivityNotFoundException。此外，该活动确实存在，但在华为的一些设备上根本无法打开。听起来，您正试图破解并修复华为EMUI可能存在的错误。即使你能检测到活动没有打开，你会怎么做？@Sharp我会弹出一个窗口，解释在设置中需要执行哪些步骤。不幸的是，这种方法很容易失败。我更喜欢另一种更好的方式。也许你可以尝试用

startActivityForResult（intent，requestCode）

启动

intent

，然后看看它是否以

onActivityResult（）

或更新的

ActivityContracts

方式成功返回。请通过编辑答案详细解释

public class MainActivity extends AppCompatActivity {

    // a boolean variable to check whether or not another activity is opened or not
    // if opened our this activity will be paused
    private boolean externalActivityOpened = false;

    // a boolean variable to filter all other condition due to which our activity
    // can be paused
    private boolean startLookingIfCurrentActivityIsPaused = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        openLocationSettings();
    }

    private void openLocationSettings() {
        Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
        // set variable to true...if activity is paused now, there is high chance
        // that it is paused because the location settings has been opened
        startLookingIfCurrentActivityIsPaused = true;
        // this solution will fail if at this very point the interruption occurs such as a phone call
        // other than that it should work fine I guess xD
        startActivity(intent);
    }

    @Override
    protected void onPause() {
        super.onPause();
        // we check to see if onpause is called after we wanted to start the location settings
        // if yes then it is almost certain that the new activity has been started
        if (startLookingIfCurrentActivityIsPaused) {
            externalActivityOpened = true;
            startLookingIfCurrentActivityIsPaused = false;
            Toast.makeText(this, "New activity has been started!", Toast.LENGTH_LONG).show();
        }
    }
}