fragment back to the end , the screen is white

Question

I have a MainActivity, it has a lots of Fragment under it.

I set the return mechanism transaction.addToBackStack(null);

The function like this:

public void switchFragment(Fragment fragment) {
    FragmentManager manager = getSupportFragmentManager();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.mainFrame, fragment, null);
    transaction.addToBackStack(null);
    transaction.commit();
}

My issue is when I click the back button to the end, the FrameLayout is white

I tried to add

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {    
        if (mainFrame==null)
            return super.onKeyDown(keyCode, event);
    }
}

It's not working. How do I avoid this white screen when I call back the Fragment to the end ? Any help would be great!

please show your xml file – scienticious Jan 23 '17 at 03:53 — scienticious, Jan 23 '17 at 03:53
i found solution ,thanks man. – Morton Jan 23 '17 at 04:07 — Morton, Jan 23 '17 at 04:07

score 5 · Answer 1 · edited Aug 13 '18 at 19:55

5

I took @ReazMushed's suggestion and changed like this:

@Override
public void onBackPressed() {
    if (getSupportFragmentManager().getBackStackEntryCount() ==1) {
        finish();
    }else{
        super.onBackPressed()
    }
}

And the white screen problem is gone!

edited Aug 13 '18 at 19:55

Amila

13
6

answered Jan 23 '17 at 04:09

Morton

5,380
18
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score 2 · Accepted Answer · answered Jan 23 '17 at 03:49

2

From your question what I've understood is, you have a set of Fragment which is launched one after one and when you press the back button, they disappears one after one. When the first Fragment reaches and you click the back button again, it shows a white screen.

If I'm correct, you might have to track if the first Fragment is reached and then finish the Activity.

Implement the onBackPressed function in your MainActivity. You might consider doing something like this.

@Override
public void onBackPressed() {
    if (getSupportFragmentManager().getBackStackEntryCount() > 0)
        getSupportFragmentManager().popBackStack();
    else
        finish();    // Finish the activity
}

answered Jan 23 '17 at 03:49

Reaz Murshed

23,691
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Yes , you are correct ,thanks for your help , but it still shows a white screen when the first Fragment reaches – Morton Jan 23 '17 at 04:02
i found the way from your suggestion , i change like this 'if(getSupportFragmentManager().getBackStackEntryCount() ==1) { finish(); }' , i avoid the white screen issue now , although i 'm not sure it's the correct solution. – Morton Jan 23 '17 at 04:07

fragment back to the end , the screen is white

2 Answers2