后退按钮时片段错误

Question

I have 3 fragment, but when first I load the fragment one and then fragment two and when I press the back button, why the fragment one and two are concat? for example picture below:

maybe, I must destroy the last fragment for new fragment. how to fix this issue? thanks.

Answer 1

Overide the on back pressed in you fragment and put you code in there.

public class MyFragment extends BaseFragment {

  /**
  * Back pressed send from activity.
  *
  * @return if event is consumed, it will return true.
  */
  @Override
  public boolean onBackPressed() {
    startActivity(new Intent(this, blabla.class));
    //or you could say finish();
    //or you could say moveTaskToBack(true);

}

Answer 2

Check the following possible conditions, please ....

• Check which Fragment method you have used, replace or Add

   FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); ft.replace(R.id.rlContainer, fragment); // replace the existing one 

• Enabled backStack support and then you explicitly load the same fragment on backPress

   FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); ft.replace(R.id.rlContainer, fragment); //ft.addToBackStack(null); // will add to the fragment stack ft.commitAllowingStateLoss(); 

If you are enabled backStack support you can check the count

FragmentManager fm = getFragmentManager(); // or 'getSupportFragmentManager();'
int count = fm.getBackStackEntryCount();
for(int i = 0; i < count; ++i) {    
   fm.popBackStack();
}