Activity com.example.myapplication.MainActivity has leaked window DecorView@f40b33[MainActivity] that was originally added here

This error occurs when an activity tries to show a dialog or a toast message after it has been destroyed or closed. The error message indicates that the view (DecorView) that was added to the activity's window is still being used even though the activity is no longer active.

To fix this error, you can try the following:

1. Avoid calling any UI-related methods after the activity has been destroyed, such as showing a dialog or a toast message.
2. Check if the activity is still running before calling any UI-related methods. You can do this by using the isFinishing() method or checking if the activity is null.
3. Use a WeakReference to hold any UI-related objects, such as dialogs or toast messages, and check if the reference is still valid before calling any methods on it.
4. Override the onDestroy() method in your activity and make sure to clean up any UI-related resources that you may have created, such as dialogs or toast messages.

By following these steps, you should be able to avoid this error and ensure that your app behaves correctly even when the activity has been destroyed.