Xamarin/.NET 7/Microsoft.macOS - Create a screenshot of all windows open.

01 Screenshot.cs

// Captures a screenshot of all windows open and saves it to pages in a PDF file.

[DllImport("/System/Library/Frameworks/QuartzCore.framework/QuartzCore")]
static extern IntPtr CGWindowListCopyWindowInfo(CGWindowListOption option, uint relativeToWindow);

IntPtr windowsPtr = CGWindowListCopyWindowInfo(CGWindowListOption.All, 0);
var windows = (NSArray)Runtime.GetNSObject(windowsPtr)!;

var images = new List<CGImage>();
foreach (var window in windows) {
    var windowNumber = (NSNumber)window.P("kCGWindowNumber");
    Console.WriteLine(window);
    var image = CGImage.ScreenImage(windowNumber.Int32Value, CGRect.Null, CGWindowListOption.IncludingWindow, CGWindowImageOption.BestResolution);
    if (image == null)
        continue;

    images.Add(image);
}
var url = new NSUrl("file:///Users/foxt/testimages/test.pdf");
var dest = CGImageDestination.Create(url, "com.adobe.pdf", images.Count);
foreach (CGImage image in images)
    dest.AddImage(image);
dest.Close();

02 NSObjectExtensions.cs

// Helper class to add a NSObject.P(string property) rather than having to NSObject.ValueForKey(new NSString(string property))
public static class NSObjectExtensions {
    public static NSObject P(this NSObject obj,string propertyName) =>
        obj.ValueForKey(new NSString(propertyName));
}