如果已经打开碎片，如何防止在导航抽屉中打开该碎片

Question

How to prevent opening a fragment in navigation drawer if that fragment is already opened. For example I have a Settings fragment in my Nav Drawer at first if click on that frag it opens so now again if I click on that it should not open the same fragment twice as this causes a problem while hitting back button.

Answer 1

You can maintain the position of the fragment in the list that is currently open. For instance, maintain a variable called mSelectedPosition , which is initialized to -1 in onCreate() . Then the code in your onItemClick() in the DrawerItemClickListener can be something like

if (position == mSelectedPosition) {
    closeDrawer();
    return;
}

mSelectedPosition = position;
// Continue your work here.

Answer 2

Possibly, you should change the new Fragment at the onDrawerClosed() callback. Maintain a member variable like, currentFragmentPosition.

public void onDrawerClosed(View view) 
{
    super.onDrawerClosed(view);

    if(clickedPosition != currentFragmentPosition)
    {
        // change Fragment
    }
    currentFragmentPosition = clickedPosition;
}