Dependency Service: set accessibility focus to other control after a button click

Question

My issue is similar to below question :

https://social.msdn.microsoft.com/Forums/en-US/ef62f3b6-4599-4853-a274-a21238c02225/dependency-service-set-accessibility-focus-after-a-button-click?forum=xamarinforms

Unable to move the focus to other control when a button is clicked. Below is the code

class OnViewVisibilityService : IOnViewVisibilityService
    {
        public void getVisibileView(Xamarin.Forms.View view)
        {
            var vRenderer = Platform.CreateRendererWithContext(view, Android.App.Application.Context);
            var view1 = vRenderer.View;
            view1.SendAccessibilityEvent(Android.Views.Accessibility.EventTypes.ViewFocused);

        }
    }

----------- calling Dependency service in a button tap event -------------------

DependencyService.Get<IOnViewVisibilityService>().getVisibileView(PageHeaderLabel);
//PageHeaderLabel is Xamarin form Label

Could anyone look into it and let me what am missing?

Answer 1

Hello,​

Welcome to our Microsoft Q&A platform!

I find use Dependence Service cannot get the TextView, So I achive it in the Custom Renderer. we should create a custom Label. Create a method called GetAccessibilityForLabel,

   public class MyLabel:Label  
       {  
           public event EventHandler GetAccessibility;  
           public void GetAccessibilityForLabel() {  
     
               if (GetAccessibility != null)  
               {  
                   GetAccessibility(this, EventArgs.Empty);  
               }  
     
           }  
     
       }  

then we can call it in the button click event,

   private void Button_Clicked(object sender, EventArgs e)  
           {  
      
               myLabel.GetAccessibilityForLabel();  
             
           }  

Then we can achieve this get Accessibility in the custom renderer with textView.SendAccessibilityEvent(EventTypes.ViewHoverEnter);.

   namespace App150.Droid  
   {  
       class MyLabelRenderer : LabelRenderer  
       {  
           public MyLabelRenderer(Context context) : base(context)  
           {  
           }  
           TextView textView;  
           MyLabel myLabel;  
           protected override void OnElementChanged(ElementChangedEventArgs<Label> e)  
           {  
               base.OnElementChanged(e);  
               if (e.NewElement != null)  
               {  
                   textView = Control as TextView;  
                   myLabel = e.NewElement as MyLabel;  
                   myLabel.GetAccessibility += OnAccessibilityRequested;  
               }  
               if (e.OldElement != null)  
               {  
                   myLabel.GetAccessibility -= OnAccessibilityRequested;  
               }      
            }  
     
           private void OnAccessibilityRequested(object sender, EventArgs e)  
           {  
                   Device.BeginInvokeOnMainThread(() => {                  
                       textView.SendAccessibilityEvent(EventTypes.ViewHoverEnter);  
                   });  
                
           }  
       }  
   }  

Best Regards,

Leon Lu

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