Changed SKGLView and Gradient test

* Fixed to call SKObject.Dispose

Xamarin.Forms.ControlGallery.WinForms/Page1.xaml

@@ -19,7 +19,7 @@
             <RowDefinition />
             <RowDefinition />
         </Grid.RowDefinitions>
-        <skia:SKCanvasView
+        <skia:SKGLView
             Grid.Column="0" Grid.Row="0"
             Grid.ColumnSpan="2"
             Grid.RowSpan="2"
@@ -70,11 +70,11 @@
             Increment="1"
             Maximum="100"
             Value="45"/>
-        <WebView 
+        <!--<WebView 
             Grid.Column="1"
             Grid.ColumnSpan="2"
             Grid.Row="4" 
-            Source="www.google.com"/>
+            Source="www.google.com"/>-->
         <Label
             Grid.Column="0" Grid.Row="5"
             Text="{Binding Source={x:Reference entry}, Path=Text}"

Xamarin.Forms.ControlGallery.WinForms/Page1.xaml.cs

@@ -22,11 +22,20 @@ namespace Xamarin.Forms.ControlGallery.WinForms
 			System.Windows.Forms.MessageBox.Show("Clicked!");
 		}
 
-		private void SKCanvasView_PaintSurface(object sender, SkiaSharp.Views.Forms.SKPaintSurfaceEventArgs e)
+		private void SKCanvasView_PaintSurface(object sender, SkiaSharp.Views.Forms.SKPaintGLSurfaceEventArgs e)
 		{
-			var p = new SKPaint();
-			p.Color = SKColors.Aqua;
-			e.Surface.Canvas.DrawCircle(100, 100, 20, p);
+			e.Surface.Canvas.Clear(SKColors.White);
+			using (var p = new SKPaint())
+			using (var shader = SKShader.CreateLinearGradient(
+				new SKPoint(0.0f, 0.0f),
+				new SKPoint(100.0f, 100.0f),
+				new [] { SKColors.Red, SKColors.Green },
+				null,
+				SKShaderTileMode.Clamp))
+			{
+				p.Shader = shader;
+				e.Surface.Canvas.DrawRect(new SKRect(0.0f, 0.0f, 100.0f, 100.0f), p);
+			}
 		}
 	}
 }

Xamarin.Forms.ControlGallery.WinForms/Program.cs

@@ -14,6 +14,8 @@ namespace Xamarin.Forms.ControlGallery.WinForms
 		[STAThread]
 		static void Main()
 		{
+			OpenTK.Toolkit.Init();
+
 			System.Windows.Forms.Application.EnableVisualStyles();
 			System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);