Is There A GridLayout SizeChanged Event In Xamarin.Android?

Question

I would like to rearrange a set of buttons when the screen size changes. Is there an event similar to SizeChanged in Xamarin.Android for a GridLayout (because GridLayout is the root of my Activity)? I would also be able to use an event that detects when the screen size changes instead. I have found the LayoutChange event, but I am worried that if I use this I will end up in some kind infinite loop due to the fact that I will be changing the layout during the event. Any ideas? Thanks.

Answer 1

Hello @Nathan Sokalski ,​

Welcome to our Microsoft Q&A platform!

In Android, the View class provides the OnSizeChanged event which will be called when the size of this view has changed. Try creating a custom GridLayout to rewrite the event. To define the function in the Activity class, you could use delegate to pass the event.

Check the code:

   public class MainActivity : AppCompatActivity  
   {  
       protected override void OnCreate(Bundle savedInstanceState)  
       {  
           base.OnCreate(savedInstanceState);  
           Xamarin.Essentials.Platform.Init(this, savedInstanceState);  
           SetContentView(Resource.Layout.activity_main);  
     
           CustomLayout layout = FindViewById<CustomLayout>(Resource.Id.parent);  
           layout.TheChangeEvent += Layout_TheChangeEvent;  
       }  
     
       private void Layout_TheChangeEvent()  
       {  
           //perform the work  
       }  
   }  

Csutom control:

   public delegate void SizeChangedEventHanlder();  
   namespace App19_7  
   {  
       public class CustomLayout : GridLayout  
       {  
           public CustomLayout(Context context) : base(context)  
           {  
           }  
     
           public CustomLayout(Context context, IAttributeSet attrs) : base(context, attrs)  
           {  
           }  
     
           public CustomLayout(Context context, IAttributeSet attrs, int defStyleAttr) : base(context, attrs, defStyleAttr)  
           {  
           }  
     
           public CustomLayout(Context context, IAttributeSet attrs, int defStyleAttr, int defStyleRes) : base(context, attrs, defStyleAttr, defStyleRes)  
           {  
           }  
     
           protected CustomLayout(IntPtr javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)  
           {  
           }  
     
           public event SizeChangedEventHanlder TheChangeEvent;  
     
           protected override void OnSizeChanged(int w, int h, int oldw, int oldh)  
           {  
               base.OnSizeChanged(w, h, oldw, oldh);  
     
               TheChangeEvent.Invoke();  
           }  
       }  
   }  

Best Regards,

Jarvan Zhang

---

If the response is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.