Try this code it should work
[assembly: ExportRenderer(typeof(NavigationPage), typeof(CustomMapRenderer))] namespace XamarinFormsMaps.Droid { public class CustomMapRenderer : NavigationPageRenderer { protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e) { base.OnElementChanged(e); var bar = (Android.Support.V7.Widget.Toolbar)typeof(NavigationPageRenderer) .GetField("_toolbar", BindingFlags.NonPublic | BindingFlags.Instance) .GetValue(this); bar.SetLogo(Resource.Drawable.icon); } } }

[assembly: ExportRenderer(typeof(NavigationPage), typeof(CustomMapRenderer))] namespace XamarinFormsMaps.Droid { public class CustomMapRenderer : NavigationPageRenderer { protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e) { base.OnElementChanged(e); var bar = (Android.Support.V7.Widget.Toolbar)typeof(NavigationPageRenderer) .GetField("_toolbar", BindingFlags.NonPublic | BindingFlags.Instance) .GetValue(this); bar.SetLogo(Resource.Drawable.icon); } } }
Try this one!