Use dynamic loading instead of DllImport to access AppKit library on macOS.

Author: hamster620

MacOS/AppKit/NSApplication.cs

@@ -73,11 +73,8 @@ static NSApplication()
     {
         if (Platform.IsNotMacOS)
             return;
-        var libHandle = NativeLibrary.Load(NativeLibraryNames.AppKit);
-        if (libHandle != IntPtr.Zero)
-        {
-            NSAppPtr = (IntPtr*)NativeLibrary.GetExport(libHandle, "NSApp");
-        }
+        var libHandle = NativeLibraryHandles.AppKit;
+        NSAppPtr = (IntPtr*)NativeLibrary.GetExport(libHandle, "NSApp");
         NSApplicationClass = Class.GetClass("NSApplication").AsNonNull();
     }
 

MacOS/NativeLibraryHandles.cs

@@ -9,6 +9,10 @@ namespace CarinaStudio.MacOS;
 public static class NativeLibraryHandles
 {
     // Constants.
+    static readonly string[] AppKitLibPaths =
+    [
+        "/System/Library/Frameworks/AppKit.framework/AppKit"
+    ];
     static readonly string[] CoreFoundationLibPaths =
     [
         "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation",
@@ -27,12 +31,20 @@ public static class NativeLibraryHandles
 
 
     // Fields.
+    static IntPtr appKitLibHandle;
     static IntPtr coreFoundationLibHandle;
     static IntPtr coreGraphicsLibHandle;
+    static bool isAppKitLibResolved;
     static bool isCoreFoundationLibResolved;
     static bool isCoreGraphicsLibResolved;
     static bool isImageIOLibResolved;
     static IntPtr imageIOLibHandle;
+    
+    
+    /// <summary>
+    /// Handle of AppKit library.
+    /// </summary>
+    public static IntPtr AppKit => GetHandle(AppKitLibPaths, ref appKitLibHandle, ref isAppKitLibResolved);
 
 
     /// <summary>

MacOS/NativeLibraryNames.cs

@@ -10,21 +10,22 @@ public static class NativeLibraryNames
     /// <summary>
     /// AppKit.
     /// </summary>
+    [Obsolete("The path to AppKit may be different between macOS, use NativeLibraryHandles.AppKit instead.")]
     public const string AppKit = "/System/Library/Frameworks/AppKit.framework/AppKit";
     /// <summary>
     /// Core Foundation.
     /// </summary>
-    [Obsolete("The path to CoreFoundation may be different between macOS, use NativeLibraryHandles.CoreFoundation instead.")]
+    [Obsolete("The path to Core Foundation may be different between macOS, use NativeLibraryHandles.CoreFoundation instead.")]
     public const string CoreFoundation = "/System/Library/Frameworks/ApplicationServices.framework/Frameworks/CoreFoundation.framework/CoreFoundation";
     /// <summary>
     /// Core Graphics.
     /// </summary>
-    [Obsolete("The path to CoreFoundation may be different between macOS, use NativeLibraryHandles.CoreGraphics instead.")]
+    [Obsolete("The path to Core Graphics may be different between macOS, use NativeLibraryHandles.CoreGraphics instead.")]
     public const string CoreGraphics = "/System/Library/Frameworks/ApplicationServices.framework/Frameworks/CoreGraphics.framework/CoreGraphics";
     /// <summary>
     /// Image I/O.
     /// </summary>
-    [Obsolete("The path to CoreFoundation may be different between macOS, use NativeLibraryHandles.ImageIO instead.")]
+    [Obsolete("The path to ImageIO may be different between macOS, use NativeLibraryHandles.ImageIO instead.")]
     public const string ImageIO = "/System/Library/Frameworks/ApplicationServices.framework/Frameworks/ImageIO.framework/ImageIO";
     /// <summary>
     /// Objective-C Runtime.