How to switch to a previous activity in Android without error message?

Question

I have 2 screens corresponding to 2 activities on my Android app. I am trying to go back to the first activity from the second screen by clicking a Back button. Even though my first activity restarts, I get an annoying pop-up message "Unfortunately the app has stopped" as my app refreshes to go back to the first activity. I would like to not have this message appear.

I have tried different variations of code and the message appears each time :

@Override
public void onBackPressed() {
    startActivity(new Intent(this, MainActivity.class));
}

or

public void finishActivity(DisplayMessageActivity v){
  Intent intent = new Intent( this, MainActivity.class );
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);   
}

or even just

public void finishActivity(DisplayMessageActivity v){
    finish();
 }

The [logcat will tell you what reason your app has stopped](http://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this). Please [edit] your question with it. — OneCricketeer, Jan 23 '17 at 20:49

score 0 · Accepted Answer · answered Jan 23 '17 at 20:51

You should read the logs to find out what the exception is and why it is occurring. Places to check:

If back navigation logic is inside an OnClickListener, something inside the OnCLickListener code is probably null.
The activity it should go to after pressing back is having a null value for something you're trying to use.
Any asynchronous calls from old activity finishing after it has been removed.

Your log should tell you exactly what it is.

How to switch to a previous activity in Android without error message?

1 Answers1