Activity has leaked window that was originally added

😱 Activity has leaked window that was originally added ❌

You're happily building your Android app, and suddenly, this error pops up:

Activity com.mypkg.myP has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44c46ff0 that was originally added here

What on earth does this mean? And more importantly, how on earth do you fix it? Don't panic! We're here to help you understand and solve this pesky issue. Let's dive in! 💪

What is this error and why does it happen?

This error is known as a "WindowLeaked" error. It occurs when an activity tries to display a dialog or a toast message after it has been destroyed or finished. The error message tells you which activity has the issue and where the window was originally added.

In simpler terms, it's like trying to talk to someone outside their house after they have already left. You're left with a window that doesn't have a home.

Common scenarios leading to this error

✅ Dialogs or toasts shown after an activity has been destroyed or finished. ✅ Asynchronous/background tasks (e.g., AsyncTasks, threads) that attempt to show UI elements after the activity is gone. ✅ Configuration changes (e.g., screen rotations) that cause activity recreation while UI elements are being shown.

How to fix it?

Now that we understand what causes this error, let's explore some solutions:

1. Dismiss dialogs or toasts before activity destruction

Make sure to dismiss any active dialogs or toasts when your activity is about to be destroyed or finished. You can do this in the onPause() or onDestroy() methods.

Here's an example using AlertDialog:

@Override
protected void onPause() {
    super.onPause();
    
    if(dialog != null && dialog.isShowing()) {
        dialog.dismiss();
    }
}

2. Cancel asynchronous/background tasks

If you're performing background tasks, such as using AsyncTask or threads, make sure to cancel them when the activity is being destroyed. This can be done in the onDestroy() method.

Here's an example using AsyncTask:

@Override
protected void onDestroy() {
    super.onDestroy();
    
    if(asyncTask != null && asyncTask.getStatus() == AsyncTask.Status.RUNNING) {
        asyncTask.cancel(true);
    }
}

3. Handle configuration changes gracefully

When a configuration change occurs (e.g., screen rotation), Android recreates the activity. You should handle these changes gracefully by saving and restoring any UI state.

You can use methods like onSaveInstanceState() and onRestoreInstanceState() to save and restore the state of UI elements.

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    
    // Save necessary data to outState
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    
    // Restore data from savedInstanceState
}

Take action and conquer this error! 🚀

Now that you have some handy solutions at your disposal, go ahead and implement them in your app. Remember to be proactive and prevent this error from occurring in the first place.

If you found this blog post helpful, don't forget to share it with your fellow Android developers who might be struggling with the same issue. Together, we can conquer the "Activity has leaked window" error once and for all. 💪

Have you encountered this error before? Do you have any other tips or tricks to share? We'd love to hear from you in the comments below! Let's keep the conversation going! 😊