create skiasharp camera overlay xamarin ios - ios

Question

I am trying to create a app that uses skiasharp on an overlay for the camera on iPhone (native). My camera stream appears nicely but no overlay. the initial viewcontroller that creates the stream looks like:
public async override void ViewDidLoad()
{
base.ViewDidLoad();
await AuthorizeCameraUse();
imagePicker = new UIImagePickerController();
// set our source to the camera
imagePicker.SourceType = UIImagePickerControllerSourceType.Camera;
// set
imagePicker.MediaTypes = new string[] { "public.image" };
imagePicker.CameraOverlayView = new CameraOverlayView();
imagePicker.ModalPresentationStyle = UIModalPresentationStyle.CurrentContext;
. . .
my CameraOverlayView looks like:
public class CameraOverlayView :SKCanvasView
{
public CameraOverlayView() : base()
{
Initialize();
}
public CameraOverlayView(CGRect frame) : base(frame) {
Initialize();
}
SKPaint paint = new SKPaint
{
Style = SKPaintStyle.Fill,
Color = SKColors.Red,
StrokeWidth = 25
};
protected void Initialize()
{
this.PaintSurface += CameraOverlayView_PaintSurface;
//using (var surface = SKSurface.Create( 640, 480, SKColorType.Rgba8888, SKAlphaType.Premul))
//{
// SKCanvas myCanvas = surface.Canvas;
// myCanvas.DrawCircle(300, 300, 100, paint);
// // Your drawing code goes here.
//}
}
private void CameraOverlayView_PaintSurface(object sender, SKPaintSurfaceEventArgs e)
{
var surface = e.Surface;
// then we get the canvas that we can draw on
var canvas = surface.Canvas;
// clear the canvas / view
canvas.Clear(SKColors.White);
// DRAWING SHAPES
// create the paint for the filled circle
var circleFill = new SKPaint
{
IsAntialias = true,
Style = SKPaintStyle.Fill,
Color = SKColors.Blue
};
// draw the circle fill
canvas.DrawCircle(100, 100, 40, circleFill);
}
}
my Paint event is never fired , if I run this code in simple example it does.

Answer 1

thanks to Russ Fustino help it turns out I was not using the CameraOverlayView (CGRect frame) : base (frame) constructor and because of that the DrawInSurface overload is not called.
Nothing to draw into. when I did this the paint event fired.