CODEWITHSUNDEEP
javaandroidandroid-intent
Sandunka Mihiran
Sandunka Mihiran

Reputation: 565

how to close main activity after closing another activity in android?

I am developing an android application. So in there I have button called "Aboutus". when I click that one it starts another activity and show corresponding view.

Here is the code for button Aboutus click event.

    aboutus.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
             Intent intent = new Intent(MainActivity.this,AboutUs.class);
             startActivity(intent);
        }

    });

}

And then in that aboutus activity I have back button.when we press that back button it will go to the main activity again. back button key event goes like this..

    back.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            Intent intent = new Intent(AboutUs.this,MainActivity.class);
            intent.putExtra("aboutus", true);
            startActivity(intent);
            finish();
            System.exit(0);
        }

    });

here i put some intent extras for some other purposes.In this case they do not matter. So and then again in mainactivity i have exit button. which should kill whole app.

and my exit button code goes like this.

exit.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
              finish();
              System.exit(0);
        }

    });

Exit button works perfectly (it ends the app) except for one scenario. if we click on aboutus and go to that activity and then press back button on that aboutus activity and then again come back to main activity and finally when i want to exit it won't kill whole app, instead it again goes to the about activity.

in conclusion, MainActivity---> click aboutus button(no problem in here.this will start aboutus activity)

Aboutus----->click back button(this also works fine. go back to main activity)

MainActivity--> Exit button (not working .it goes to aboutus activity again)

So how to fix this problem?

Upvotes: 0

Views: 2141

Answers (2)

j2emanue
j2emanue

Reputation: 62519

i dont see why you have to start MainActivity.java ...the user can just hit the back button as long as its on the activity stack. Also The system.exit(0) is bad. Just let the app finish gracefully with finish().
if you want to pass something to the activity when aboutUS is done, you can look up onNewIntent() method.

Upvotes: 2

Krupal Shah
Krupal Shah

Reputation: 9187

use intent flag ACTIVITY_CLEAR_TOP to clear all activities on top of it:

            Intent intent = new Intent(AboutUs.this,MainActivity.class);
            intent.putExtra("aboutus", true);
            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
            startActivity(intent);

FLAG_ACTIVITY_CLEAR_TOP From the doc:

If set, and the activity being launched is already running in the current task, then instead of launching a new instance of that activity, all of the other activities on top of it will be closed and this Intent will be delivered to the (now on top) old activity as a new Intent.

Upvotes: 0

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