android: Handle Application Crash and start a part

问题:

I have an app and if the app crashes in a particular activity, it restarts at one of the intermediate parent activities.

This is a problem for me since I have some inputted user info that is lost upon crash.

Is there any way to force the app to start from the launcher screen after restarting from a crash?

Thanks.

回答1:

Proposed Solution 1 -

Add this tag android:clearTaskOnLaunch="true" in the manifest.xml file to your main activity which should always launch.

Probable Reason why it did not work

When the application crashes, it throws an Exception and we need to handle the Exception and otherwise we would not get the expected behavior

Proposed Solution 2

Try to handle any uncaught Exception and tell the system what to do. To implement this, try the below steps.

1. Create a class extending Application Class
2. Handle uncaughtException in your Application subclass.
3. In your launcher Activity, call your Application class.
4. After catching an Exception, start your main Activity (as per your requirement).

Code Sample

Step 1 and 2

package com.casestudy.intentsandfilter;

import android.app.Application;
import android.content.Intent;

public class MyApplication extends Application
{
    @Override
    public void onCreate() {

        super.onCreate();

        Thread.setDefaultUncaughtExceptionHandler(
            new Thread.UncaughtExceptionHandler() {
                @Override
                public void uncaughtException (Thread thread, Throwable e) {
                    handleUncaughtException (thread, e);
                }
            });
    }

    private void handleUncaughtException (Thread thread, Throwable e) {

        // The following shows what I'd like, though it won't work like this.
        Intent intent = new Intent (getApplicationContext(),DrawView.class);
        startActivity(intent);

        // Add some code logic if needed based on your requirement
    }
}

Step 3

public class MainActivity extends Activity {

    protected MyApplication app;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        // Get the application instance
        app = (MyApplication)getApplication();

        .............
    }
}

Step 4

Modify the below method as per your requirement

private void handleUncaughtException (Thread thread, Throwable e) {

    // The following shows what I'd like, though it won't work like this.
    Intent intent = new Intent (getApplicationContext(), HomeActivity.class);
    startActivity(intent);

    // Add some code logic if needed based on your requirement
}

回答2:

I would recommend using library such as

https://github.com/Ereza/CustomActivityOnCrash

As the library takes care of other stuff along with different versions of android.

回答3:

Maybe there's no way to do that but you can flag it so you know if the activity was started through user action or if it was just started after a crash.

i.e when you start the parent activity, pass something into the startActivity intent. If that isn't there then it was started after the crash.

回答4:

I managed to start my main activity with intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); like this:

private void handleUncaughtException (Thread thread, Throwable e)
  {
    Intent intent = new Intent (getApplicationContext(), MainActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
  }

回答5:

first create and set the App class in your AndroidManifest.xml and

     android:name=".App"
     android:clearTaskOnLaunch="true"

then put this code in the App class

public class App extends Application {
@Override
public void onCreate() {
    super.onCreate();
     Thread.setDefaultUncaughtExceptionHandler(
            new Thread.UncaughtExceptionHandler() {
                @Override
                public void uncaughtException(Thread thread, Throwable e) {
                    Log.d("AppCrash", "Error just lunched ");
                }
            });
}}

Debug Log Screen Shoot