Force Edittext To Lose Focus When Back Pressed

I'm trying to force the EditText control to lose focus when the user presses the back button to hide the keyboard. There are many questions similar to this already, but after sever

Solution 1:

In my experience onBackPressed() (at least the default @Override one in an activity) will not normally fire when pushing the back button to close the keyboard. As far as I know it will only fire when a Back press would initiate a finish() on the current activity.

Below is a kind of "hacky" way to know when the keyboard is shown/hidden by monitoring the change in the view size. You must also set the Activity to android:windowSoftInputMode="adjustResize" in the AndroidManifest.xml.

finalViewactivityRootView= findViewById("Your main View");
    activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(newOnGlobalLayoutListener() {
    @OverridepublicvoidonGlobalLayout() {
        Rectr=newRect();
        //r will be populated with the coordinates of your view that area still visible.
        activityRootView.getWindowVisibleDisplayFrame(r);

        intheightDiff= activityRootView.getRootView().getHeight() - (r.bottom - r.top);
        if (heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...//Keyboard is shown


        }
        if(heightDiff <= 100) {
            //Keybaord not shown
        }
     }
    });

Solution 2:

With sincere thanks to @Shadesblade (and Xamarin's sample code), my EditTexts now unfocus! Here's the Xamarin-ized solution:

To your activity, add this class:

classGlobalLayoutListener : Java.Lang.Object, ViewTreeObserver.IOnGlobalLayoutListener
{
    Action on_global_layout;
    publicGlobalLayoutListener (Action onGlobalLayout)
    {
        on_global_layout = onGlobalLayout;
    }

    publicvoidOnGlobalLayout ()
    {
        on_global_layout ();
    }
}

Add a class variable to hold the View so that the delegate can access it:

View _rootview;

In your OnCreate() add:

GlobalLayoutListenergll=newGlobalLayoutListener(
    delegate {
        Android.Graphics.Rectr=newAndroid.Graphics.Rect();
        _rootView.GetWindowVisibleDisplayFrame(r);
        intheightDiff= _rootView.RootView.Height - (r.Bottom - r.Top);
        if (heightDiff < 100)
        {
            if (Window.CurrentFocus != null)
                Window.CurrentFocus.ClearFocus();
        }
    });

_rootView = FindViewById<View>(Resource.Id.relativeLayoutOrder);
_rootView.ViewTreeObserver.AddOnGlobalLayoutListener(gll);

I expect to need to dork around with the heightDiff level and/or have to add some rotation checking, but I haven't done any rotation support at this point, so I can punt that until later.

Thank you again! *happy dance*

Solution 3:

adding on to Shadesblade's answer, if you are using a scrollview, his answer needs a change to work, because not all of the scrollview is showing on screen. so instead of doing

int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);

you should do

int heightDiff = Utils.getScreenHeight(SearchActivity.this) - (r.bottom - r.top);

where Utils.getScreenHeight is this:

publicstaticintgetScreenHeight(Context c) {
    if (screenHeight == 0) {
        WindowManagerwm= (WindowManager) c.getSystemService(Context.WINDOW_SERVICE);
        Displaydisplay= wm.getDefaultDisplay();
        Pointsize=newPoint();
        display.getSize(size);
        screenHeight = size.y;
        screenWidth = size.x;
    }
    return screenHeight;
}