HybridWebView update (#540)

* Call .NET methods from JS

* Simplify code.

9.0/UserInterface/Views/HybridWebViewDemo/HybridWebViewDemo/MainPage.xaml.cs

@@ -10,7 +10,7 @@ public partial class MainPage : ContentPage
     public MainPage()
     {
         InitializeComponent();
-        hybridWebView.SetInvokeJavaScriptTarget<DotNetMethods>(new DotNetMethods(this));
+        hybridWebView.SetInvokeJavaScriptTarget(this);
     }
 
     private void OnSendMessageButtonClicked(object sender, EventArgs e)
@@ -61,6 +61,32 @@ private void hybridWebView_RawMessageReceived(object sender, HybridWebViewRawMes
         Dispatcher.Dispatch(() => editor.Text += Environment.NewLine + e.Message);
     }
 
+    public void DoSyncWork()
+    {
+        Debug.WriteLine("DoSyncWork");
+    }
+
+    public void DoSyncWorkParams(int i, string s)
+    {
+        Debug.WriteLine($"DoSyncWorkParams: {i}, {s}");
+    }
+
+    public string DoSyncWorkReturn()
+    {
+        Debug.WriteLine("DoSyncWorkReturn");
+        return "Hello from C#!";
+    }
+
+    public SyncReturn DoSyncWorkParamsReturn(int i, string s)
+    {
+        Debug.WriteLine($"DoSyncWorkParamReturn: {i}, {s}");
+        return new SyncReturn
+        {
+            Message = "Hello from C#!" + s,
+            Value = i
+        };
+    }
+
     public class ComputationResult
     {
         public double result { get; set; }
@@ -78,42 +104,6 @@ internal partial class HybridSampleJSContext : JsonSerializerContext
         // for trimmed builds.    
     }
 
-    private class DotNetMethods
-    {
-        MainPage _mainPage;
-
-        public DotNetMethods(MainPage mainPage)
-        {
-            _mainPage = mainPage;
-        }
-
-        public void DoSyncWork()
-        {
-            Debug.WriteLine("DoSyncWork");
-        }
-
-        public void DoSyncWorkParams(int i, string s)
-        {
-            Debug.WriteLine($"DoSyncWorkParams: {i}, {s}");
-        }
-
-        public string DoSyncWorkReturn()
-        {
-            Debug.WriteLine("DoSyncWorkReturn");
-            return "Hello from C#!";
-        }
-
-        public SyncReturn DoSyncWorkParamsReturn(int i, string s)
-        {
-            Debug.WriteLine($"DoSyncWorkParamReturn: {i}, {s}");
-            return new SyncReturn
-            {
-                Message = "Hello from C#!" + s,
-                Value = i
-            };
-        }
-    }
-
     public class SyncReturn
     {
         public string? Message { get; set; }