SkiaSharp.Views.Maui.SkCanvasView is not drawing on physical iOS devices

[whodges]

Hello,

I've been trying to get SkCanvasView working on my iPad, and I've run into the same problem as described here: #341, but with MAUI. On Windows and in the simulators, the canvas in my sample app works (i.e., it paints and show up as a red square). On my physical iPad, the canvas never fires the PaintSurface event, and so ends up black. I can tell it's there at least because of the position of the 'Invalidate' button I added; it's just not drawing.

My MainPage.xaml:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:skia="clr-namespace:SkiaSharp.Views.Maui.Controls;assembly=SkiaSharp.Views.Maui.Controls"
             x:Class="MauiSample.MainPage">

    <ScrollView>
        <VerticalStackLayout>

            <skia:SKCanvasView
                x:Name="SampleCanvas"
                EnableTouchEvents="true"
                Touch="SampleCanvas_Touch"
                PaintSurface="SampleCanvas_PaintSurface"
                HeightRequest="512"
                WidthRequest="512">
            </skia:SKCanvasView>

            <Button
                x:Name="InvalidateBtn"
                Text="Invalidate"
                SemanticProperties.Hint="Invalidates the canvas"
                Clicked="InvalidateBtn_Clicked"
                HorizontalOptions="Center" >
            </Button>

        </VerticalStackLayout>
    </ScrollView>

</ContentPage>

My MainPage.xaml.cs:

using SkiaSharp;
using SkiaSharp.Views.Maui;

namespace MauiSample;

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
    }

    private void SampleCanvas_Touch(object sender, SKTouchEventArgs e)
    {
        SampleCanvas.InvalidateSurface();
    }

    private void SampleCanvas_PaintSurface(object sender, SKPaintSurfaceEventArgs e)
    {
        e.Surface.Canvas.DrawColor(new SKColor(255, 0, 0));
        return;
    }

    private void InvalidateBtn_Clicked(object sender, EventArgs e)
    {
        SampleCanvas.InvalidateSurface();
    }
}

And I've called UseSkiaSharp() in the app builder.

For the record, the Touch event isn't firing on the iPad either (it does on Windows). I'm using Visual Studio Pro 17.4.0 Preview 4.0, and Skia.Views.Maui.Controls 2.88.3. Any insight is appreciated; perhaps I'm missing something obvious. Screenshots of my output:

Windows:

iPad:

EDIT: Fixed my crappy code block formatting.

[taublast]

Maybe try

				MainThread.BeginInvokeOnMainThread(() =>
					{
				             SampleCanvas.InvalidateSurface();
					});

 

[lobbo232]

hey @whodges did you ever get this to work?

[whodges]

It's been a minute, so i went back and made a new .NET 8 MAUI app and used the code above for MainPage with the latest SkiaSharp packages from nuget. tried it on my iphone and ipad - both worked. so I'm not sure when it started working, but it does now!

[lobbo232]

Hmm, I'm running .NET 9 and it isn't working for me