Android每X秒运行一次服务线程
我想在Android服务中创建一个每X秒运行一次的线程 我目前正在使用postdelayed方法,但它似乎确实落后于我的应用程序Android每X秒运行一次服务线程,android,multithreading,timer,Android,Multithreading,Timer,我想在Android服务中创建一个每X秒运行一次的线程 我目前正在使用postdelayed方法,但它似乎确实落后于我的应用程序 @Override public int onStartCommand(Intent intent, int flags, int startId){ super.onStartCommand(intent, flags, startId); startRepeatingTask(); return startId; } private
@Override
public int onStartCommand(Intent intent, int flags, int startId){
super.onStartCommand(intent, flags, startId);
startRepeatingTask();
return startId;
}
private final static int INTERVAL = 20000; //20 milliseconds
Handler m_handler = new Handler();
Runnable m_handlerTask = new Runnable()
{
@Override
public void run() {
// this is bad
m_handler.postDelayed(m_handlerTask, INTERVAL);
}
};
void startRepeatingTask()
{
m_handlerTask.run();
}
void stopRepeatingTask()
{
m_handler.removeCallbacks(m_handlerTask);
stopSelf();
}
我想做一个像这样的新线程:
public void threadRun()
{
Thread triggerService = new Thread(new Runnable(){
public void run(){
Looper.prepare();
try{
//do stuff here?
}catch(Exception ex){
System.out.println("Exception in triggerService Thread -- "+ex);
}//end catch
}//end run
}, "aThread");
triggerService.start();
//perhaps do stuff here with a timer?
timer1=new Timer();
timer1.scheduleAtFixedRate(new methodTODOSTUFF(), 0, INTERVAL);
}
我不确定以一定间隔运行后台线程的最佳方法,敬请谅解 每隔几秒钟启动一个
runnable
会有一些延迟,不管你用什么方式分割它,不是吗?我不明白为什么处理程序
不能正常工作
但你可能会遇到一些麻烦,因为你
void startRepeatingTask()
{
m_handlerTask.run();
}
相反,您应该使用处理程序并执行以下操作:
void startRepeatingTask()
{
m_handler.post(m_handlerTask);
}
(顺便说一句,Java中的约定是使用驼峰大小写,而不是蛇形大小写。因此,它应该是mHandler,而不是m_handler,等等。只是告诉你,因为它可能会让一些人更容易阅读代码。)下面是我如何运行重复线程的,你会看到它每1秒循环一次。我认为这种方法没有滞后性
final Thread t = new Thread(new RepeatingThread());
t.start();
班级:
import android.os.Handler;
public class RepeatingThread implements Runnable {
private final Handler mHandler = new Handler();
public RepeatingThread() {
}
@Override
public void run() {
mHandler.postDelayed(this, 1000);
}
}
有许多替代方法可以做到这一点。就个人而言,我更喜欢使用:
MyService.java
public class MyService extends Service {
public static final int notify = 5000; //interval between two services(Here Service run every 5 seconds)
int count = 0; //number of times service is display
private Handler mHandler = new Handler(); //run on another Thread to avoid crash
private Timer mTimer = null; //timer handling
@Override
public IBinder onBind(Intent intent) {
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public void onCreate() {
if (mTimer != null) // Cancel if already existed
mTimer.cancel();
else
mTimer = new Timer(); //recreate new
mTimer.scheduleAtFixedRate(new TimeDisplay(), 0, notify); //Schedule task
}
@Override
public void onDestroy() {
super.onDestroy();
mTimer.cancel(); //For Cancel Timer
Toast.makeText(this, "Service is Destroyed", Toast.LENGTH_SHORT).show();
}
//class TimeDisplay for handling task
class TimeDisplay extends TimerTask {
@Override
public void run() {
// run on another thread
mHandler.post(new Runnable() {
@Override
public void run() {
// display toast
Toast.makeText(MyService.this, "Service is running", Toast.LENGTH_SHORT).show();
}
});
}
}
}
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this, MyService.class)); //start service which is MyService.java
}
}
MainActivity.java
public class MyService extends Service {
public static final int notify = 5000; //interval between two services(Here Service run every 5 seconds)
int count = 0; //number of times service is display
private Handler mHandler = new Handler(); //run on another Thread to avoid crash
private Timer mTimer = null; //timer handling
@Override
public IBinder onBind(Intent intent) {
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public void onCreate() {
if (mTimer != null) // Cancel if already existed
mTimer.cancel();
else
mTimer = new Timer(); //recreate new
mTimer.scheduleAtFixedRate(new TimeDisplay(), 0, notify); //Schedule task
}
@Override
public void onDestroy() {
super.onDestroy();
mTimer.cancel(); //For Cancel Timer
Toast.makeText(this, "Service is Destroyed", Toast.LENGTH_SHORT).show();
}
//class TimeDisplay for handling task
class TimeDisplay extends TimerTask {
@Override
public void run() {
// run on another thread
mHandler.post(new Runnable() {
@Override
public void run() {
// display toast
Toast.makeText(MyService.this, "Service is running", Toast.LENGTH_SHORT).show();
}
});
}
}
}
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this, MyService.class)); //start service which is MyService.java
}
}
在AndroidManifest.xml
AndroidManifest.xml
<service android:name=".MyService" android:enabled="true" android:exported="true"></service>
嘿,我基本上是这样做的,我用了一个TimerTask:)嗨,我用这个,它工作得很好,但我如何停止任务?@Kevin,使用它,即使在应用程序关闭时它也会运行吗?小心,我有一种只启动一次的方法,没有延迟这种方式你能提供一些解释这个代码吗?这里的提示是使用服务并实现一个计时器,在一段时间间隔内运行TimerTask。我这里的例子是我每5秒钟吃一次吐司和时间