DllNotFoundException OpenCvSharpExtern when running .NET MAUI on MacOS

[LoooooKe]

Summary of your issue

DllNotFoundException OpenCvSharpExtern when running .NET MAUI on MacOS 15.1. If I run a simple App with Avalonia instead of MAUI everything works as intended.

I tracked the issue to

opencvsharp/src/OpenCvSharp/Internal/PInvoke/NativeMethods/NativeMethods.cs

Line 88 in 352c778

if (IsUnix())

When ruuning MAUI on MacOS, IsUnix() returns False because MacCatalyst is not in the list on L188.

It should be an easy fix to add MacCatalyst to this List.

Environment

• MacOS Sequoia 15.1, XCode 16.1
• .NET 9
• MAUI 9.0.0
• OpenCvSharp4 4.10.20241108
• OpenCvSharp4.runtime.osx_arm64 4.8.1-rc

What did you do when you faced the problem?

Generate simple MAUI App by Rider, install OpenCvSharp & osx.runtime. Somewhere initialize OpenCv (eg. VideoCapture.FromCamera). Exception occurs during initialization of OpenCvSharp.

Example code:

Console.WriteLine($"IsOSX: {RuntimeInformation.IsOSPlatform(OSPlatform.OSX)}");
Console.WriteLine($"IsMacCatalyst: {System.OperatingSystem.IsMacCatalyst()}");
Console.WriteLine($"IsLinux: {System.OperatingSystem.IsLinux()}");
cap = VideoCapture.FromCamera(0);
if(cap.IsOpened())
    Console.Out.WriteLine("Cap is opened");

Output:

2024-11-17 22:45:27.548 MauiTest[34843:374890] IsOSX: False
2024-11-17 22:45:27.548 MauiTest[34843:374890] IsMacCatalyst: True
2024-11-17 22:45:27.548 MauiTest[34843:374890] IsLinux: False

What did you intend to be?

App and VideoCapture should start without any Exceptions.

[unalone]

The problem is caused by this fact:

On Maui, the runtime is MacCatalyst not OSX, so the IsUnix need to change to support MacCatalyst, otherwise it will assume the platform is Windows