How to pause / sleep thread or process in Android?
I use this:
Thread closeActivity = new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(3000);
// Do some stuff
} catch (Exception e) {
e.getLocalizedMessage();
}
}
});
I use CountDownTime
new CountDownTimer(5000, 1000) {
@Override
public void onTick(long millisUntilFinished) {
// do something after 1s
}
@Override
public void onFinish() {
// do something end times 5s
}
}.start();
One solution to this problem is to use the Handler.postDelayed() method. Some Google training materials suggest the same solution.
@Override
public void onClick(View v) {
my_button.setBackgroundResource(R.drawable.icon);
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
my_button.setBackgroundResource(R.drawable.defaultcard);
}
}, 2000);
}
However, some have pointed out that the solution above causes a memory leak because it uses a non-static inner and anonymous class which implicitly holds a reference to its outer class, the activity. This is a problem when the activity context is garbage collected.
A more complex solution that avoids the memory leak subclasses the Handler
and Runnable
with static inner classes inside the activity since static inner classes do not hold an implicit reference to their outer class:
private static class MyHandler extends Handler {}
private final MyHandler mHandler = new MyHandler();
public static class MyRunnable implements Runnable {
private final WeakReference<Activity> mActivity;
public MyRunnable(Activity activity) {
mActivity = new WeakReference<>(activity);
}
@Override
public void run() {
Activity activity = mActivity.get();
if (activity != null) {
Button btn = (Button) activity.findViewById(R.id.button);
btn.setBackgroundResource(R.drawable.defaultcard);
}
}
}
private MyRunnable mRunnable = new MyRunnable(this);
public void onClick(View view) {
my_button.setBackgroundResource(R.drawable.icon);
// Execute the Runnable in 2 seconds
mHandler.postDelayed(mRunnable, 2000);
}
Note that the Runnable
uses a WeakReference to the Activity, which is necessary in a static class that needs access to the UI.
You can try this one it is short
SystemClock.sleep(7000);
WARNING: Never, ever, do this on a UI thread.
Use this to sleep eg. background thread.
Full solution for your problem will be: This is available API 1
findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(final View button) {
button.setBackgroundResource(R.drawable.avatar_dead);
final long changeTime = 1000L;
button.postDelayed(new Runnable() {
@Override
public void run() {
button.setBackgroundResource(R.drawable.avatar_small);
}
}, changeTime);
}
});
Without creating tmp Handler. Also this solution is better than @tronman because we do not retain view by Handler. Also we don't have problem with Handler created at bad thread ;)
Documentation
public static void sleep (long ms)
Added in API level 1
Waits a given number of milliseconds (of uptimeMillis) before returning. Similar to sleep(long), but does not throw InterruptedException; interrupt() events are deferred until the next interruptible operation. Does not return until at least the specified number of milliseconds has elapsed.
Parameters
ms to sleep before returning, in milliseconds of uptime.
Code for postDelayed from View class:
/**
* <p>Causes the Runnable to be added to the message queue, to be run
* after the specified amount of time elapses.
* The runnable will be run on the user interface thread.</p>
*
* @param action The Runnable that will be executed.
* @param delayMillis The delay (in milliseconds) until the Runnable
* will be executed.
*
* @return true if the Runnable was successfully placed in to the
* message queue. Returns false on failure, usually because the
* looper processing the message queue is exiting. Note that a
* result of true does not mean the Runnable will be processed --
* if the looper is quit before the delivery time of the message
* occurs then the message will be dropped.
*
* @see #post
* @see #removeCallbacks
*/
public boolean postDelayed(Runnable action, long delayMillis) {
final AttachInfo attachInfo = mAttachInfo;
if (attachInfo != null) {
return attachInfo.mHandler.postDelayed(action, delayMillis);
}
// Assume that post will succeed later
ViewRootImpl.getRunQueue().postDelayed(action, delayMillis);
return true;
}