Answers

• Yelinzh Member, Xamarin Team Xamurai

  February 2020

  On Navigation pages, for Android, set the AutomationProperties.Name & AutomationProperties.HelpText in order to enable the back button to be screen readable.

  Tutorial:
  https://www.mfractor.com/blogs/news/accessibility-in-xamarin-forms

  0
• Poli97 Member ✭✭

  February 2020

  @Jarvan said:
  On Navigation pages, for Android, set the AutomationProperties.Name & AutomationProperties.HelpText in order to enable the back button to be screen readable.

  Tutorial:
  https://www.mfractor.com/blogs/news/accessibility-in-xamarin-forms

  Yes I know how to set the accessibility name, I just don't know how to set it to the back button in navbar, since it is not an instance, I don't know how to retrieve this "backbutton" element

  0
• Yelinzh Member, Xamarin Team Xamurai

  February 2020 Accepted Answer

  Try to create page custom renderer to get the toolbar and set the Accessibility.

  [assembly: ExportRenderer(typeof(ContentPage), typeof(NavigationPageRendererDroid))]
  namespace App1.Droid
  {
      public class NavigationPageRendererDroid : PageRenderer
      {
          public NavigationPageRendererDroid(Context context) : base(context)
          {
          }
  
          protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Page> e)
          {
              base.OnElementChanged(e);
  
              var context = (Activity)Xamarin.Forms.Forms.Context;
              var toolbar = context.FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
  
              toolbar.AnnounceForAccessibility("");
          }
      }
  }
  

  5
• JonAlza ESMember ✭✭✭

  May 2020

  I have the same problem about "unlabeled button". Is it possible to get back button reference from xamarin.forms? There is no way to do it without programming in android project?

  0
• Poli97 Member ✭✭

  May 2020

  @JonAlza said:
  I have the same problem about "unlabeled button". Is it possible to get back button reference from xamarin.forms? There is no way to do it without programming in android project?

  Another way that I figured out is by creating my own navbar view, using NavigationPage.SetTitleView(this, myCustonNavbar) , in which I insert my ount back button with my own Accessibility name

  0
• JonAlza ESMember ✭✭✭

  May 2020

  And using the accepted answer, how do you set accessibility properties for the back button?

  0
• Poli97 Member ✭✭

  May 2020

  @JonAlza said:
  And using the accepted answer, how do you set accessibility properties for the back button?

  In the accepted answer you are using custom renderers. So when you are on the Android custom renderer you use the Android C# method to set the accessible name of a View, which is View.ContentDescription (https://docs.microsoft.com/en-us/dotnet/api/android.views.view.contentdescription?view=xamarin-android-sdk-9#Android_Views_View_ContentDescription), and when you are on the iOS custom renderer you use the iOS C# method UIView.AccessibilityLabel (https://docs.microsoft.com/it-it/dotnet/api/uikit.uiview.accessibilitylabel?view=xamarin-ios-sdk-12#UIKit_UIView_AccessibilityLabel)

  0
• JonAlza ESMember ✭✭✭

  May 2020

  @Poli97 said:

  @JonAlza said:
  And using the accepted answer, how do you set accessibility properties for the back button?

  In the accepted answer you are using custom renderers. So when you are on the Android custom renderer you use the Android C# method to set the accessible name of a View, which is View.ContentDescription (https://docs.microsoft.com/en-us/dotnet/api/android.views.view.contentdescription?view=xamarin-android-sdk-9#Android_Views_View_ContentDescription), and when you are on the iOS custom renderer you use the iOS C# method UIView.AccessibilityLabel (https://docs.microsoft.com/it-it/dotnet/api/uikit.uiview.accessibilitylabel?view=xamarin-ios-sdk-12#UIKit_UIView_AccessibilityLabel)

  Thank you Poli97, NavigationContentDescription property is what I needed! So in OnElementChanged():

  toolbar.NavigationContentDescription = "Go back";
  

  0
• Poli97 Member ✭✭

  May 2020

  @JonAlza said:

  @Poli97 said:

  @JonAlza said:
  And using the accepted answer, how do you set accessibility properties for the back button?

  In the accepted answer you are using custom renderers. So when you are on the Android custom renderer you use the Android C# method to set the accessible name of a View, which is View.ContentDescription (https://docs.microsoft.com/en-us/dotnet/api/android.views.view.contentdescription?view=xamarin-android-sdk-9#Android_Views_View_ContentDescription), and when you are on the iOS custom renderer you use the iOS C# method UIView.AccessibilityLabel (https://docs.microsoft.com/it-it/dotnet/api/uikit.uiview.accessibilitylabel?view=xamarin-ios-sdk-12#UIKit_UIView_AccessibilityLabel)

  Thank you Poli97, NavigationContentDescription property is what I needed! So in OnElementChanged():

  toolbar.NavigationContentDescription = "Go back";
  

  I didn't do it in that way but I think it should work too, in this way you have to get the toolbar first, follow @Jarvan answer to do that

  0
• JonAlza ESMember ✭✭✭

  May 2020

  @Poli97 said:

  @JonAlza said:

  @Poli97 said:

  @JonAlza said:
  And using the accepted answer, how do you set accessibility properties for the back button?

  In the accepted answer you are using custom renderers. So when you are on the Android custom renderer you use the Android C# method to set the accessible name of a View, which is View.ContentDescription (https://docs.microsoft.com/en-us/dotnet/api/android.views.view.contentdescription?view=xamarin-android-sdk-9#Android_Views_View_ContentDescription), and when you are on the iOS custom renderer you use the iOS C# method UIView.AccessibilityLabel (https://docs.microsoft.com/it-it/dotnet/api/uikit.uiview.accessibilitylabel?view=xamarin-ios-sdk-12#UIKit_UIView_AccessibilityLabel)

  Thank you Poli97, NavigationContentDescription property is what I needed! So in OnElementChanged():

  toolbar.NavigationContentDescription = "Go back";
  

  I didn't do it in that way but I think it should work too, in this way you have to get the toolbar first, follow @Jarvan answer to do that

  Yes, sure, I did it like this:

      protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
      {
          base.OnElementChanged(e);
  
          Activity context = (Activity)this.Context;
          var toolbar = context.FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
  
          toolbar.NavigationContentDescription = "Go back";
      }
  

  But, is there a way to get directly button's reference?

  0
• Poli97 Member ✭✭

  May 2020

  @JonAlza said:

  @Poli97 said:

  @JonAlza said:

  @Poli97 said:

  @JonAlza said:
  And using the accepted answer, how do you set accessibility properties for the back button?

  In the accepted answer you are using custom renderers. So when you are on the Android custom renderer you use the Android C# method to set the accessible name of a View, which is View.ContentDescription (https://docs.microsoft.com/en-us/dotnet/api/android.views.view.contentdescription?view=xamarin-android-sdk-9#Android_Views_View_ContentDescription), and when you are on the iOS custom renderer you use the iOS C# method UIView.AccessibilityLabel (https://docs.microsoft.com/it-it/dotnet/api/uikit.uiview.accessibilitylabel?view=xamarin-ios-sdk-12#UIKit_UIView_AccessibilityLabel)

  Thank you Poli97, NavigationContentDescription property is what I needed! So in OnElementChanged():

  toolbar.NavigationContentDescription = "Go back";
  

  I didn't do it in that way but I think it should work too, in this way you have to get the toolbar first, follow @Jarvan answer to do that

  Yes, sure, I did it like this:

      protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
      {
          base.OnElementChanged(e);
  
          Activity context = (Activity)this.Context;
          var toolbar = context.FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
  
          toolbar.NavigationContentDescription = "Go back";
      }
  

  But, is there a way to get directly button's reference?

  I don't thinks so, this is why in my project I ended up using NavigationPage.SetTitleView creating my own navbar view with my own button

  0