I am building a 3D application with Silverlight 5. I have a DrawingSurface which calls a method. However, when I add a navigation:Frame to my XAML, I then get an error thrown.
Here is the method in question:
private void DrawingSurface_Draw(object sender, DrawEventArgs e)
{
GraphicsDevice device = GraphicsDeviceManager.Current.GraphicsDevice;
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer,
new Microsoft.Xna.Framework.Color(0, 0, 0, 0), 10.0f, 0);
device.SetVertexBuffer(_vertexBuffer);
device.SetVertexShader(_vertexShader);
device.SetPixelShader(_pixelShader);
device.Textures[0] = _texture;
device.SamplerStates[0] = SamplerState.LinearClamp;
device.DrawPrimitives(PrimitiveType.TriangleList, 0,
_vertexBuffer.VertexCount / 3);
device.SetVertexShaderConstantFloat4(0, ref _viewProjection);
e.InvalidateSurface();
}
The error is at the line device.DrawPrimitives(PrimitiveType.TriangleList, 0, _vertexBuffer.VertexCount / 3);
. The error is that "NullReferenceException was unhandled by user code." It does not occur without the navigation:Frame.