我按下后如何关闭应用程序？

Question

I'm installing my app then save data using Main Activity and going to another Fragment activity.Next time I'm starting my App always preview second Fragment then I press back going to Main Activity But I don't want to go Main Activity.I want press back button close My App.I try this

@Override
public void onResume() {
    super.onResume();

    getView().setFocusableInTouchMode(true);
    getView().requestFocus();
    getView().setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                // handle back button's click listener
                Toast.makeText(getActivity(), "Back press", Toast.LENGTH_SHORT).show();
                return true;
            }
            return false;
        }
    });

}

Answer 1

在您的Mainactivity中，在用于启动第二项活动的startActivity()行之后，添加以下this.finish();

Answer 2

try some like this in your onBackPress method

@Override
    public void onBackPressed() {
        Intent intent = new Intent(Intent.ACTION_MAIN);
        //to clear all old opened activities 
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
        finish();
    }

Answer 3

--Simplest way to close/exit app :

@Override
    public void onBackPressed() {
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        intent.addCategory(Intent.CATEGORY_HOME);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
        finish();
    }

Answer 4

Try this :

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
       }

Answer 5

I believe this thread can help you: Android: Quit application when press back button

Let's say your Main Activity is B and the Fragment activity is A. Then, you must clear the stack of activities and leave only A on the stack. Use this:

Intent launchNextActivity;
launchNextActivity = new Intent(B.class, A.class);
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);                  
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(launchNextActivity);

Answer 6

override onBackPressed method in your main activity

@Override public void onBackPressed() { super.onBackPressed(); finish(); }