Is there an option for screen capture and recording?

[wnstngs]

I am interested in the ability to capture a screen (screenshot), as well as to record a screen (as well as an arbitrary part of the screen) with and without sound (without using the screen recording picker from UWP).

[dhoehna]

Hi wnstngs,

Are you wondering if Windows App SDK has an option to record the screen, or are you wondering how to, in general, record the screen, or something else?

[wnstngs]

I know how to do it using 'classic' Windows API and GDI. Using WinUI 3 I don't know how to do this and if it is even possible to capture and record the screen. I know that UWP (WinUI 2) has a way to record screen or window, but only using their API with a ready-made picker. I don't like this way and I wonder if WinUI 3 offers more freedom in this matter.

[dhoehna]

I see. Sorry, I didn't understand that you were looking for a way to do this in WinUi3. @MikeHillberg does WinUI3 have an API to capture the screen?

[MikeHillberg]

I think it's possible with GraphicsCaptureItem.TryCreateFromWindowId, but it's complicated today ... You can get a WindowID from an hwnd with GetWindowIdFromWindow, and get an hwnd from a Xaml Window with IWindowNative.

[unboundin]

@MikeHillberg do you have any links to samples for using these methods?

[castorix]

There are many ways.
GDI, GDI+, DirectX (D3DXSaveSurfaceToFile or D3D11), ... for a simple Screen Capture (can be used with a WriteableBitmap),
Sink Writer for video capture,
Desktop Duplication API, ...

[castorix]

The resource seems to have the D3D11_RESOURCE_MISC_SHARED_KEYEDMUTEX flag
and apparently from MSDN, I would need to call IDXGIKeyedMutex::AcquireSync and ReleaseSync APIs.
I will try to add them, but not easy to debug as I cannot reproduce the crash.

[rcohn]

Since the last set of changes added, I have not been able to reproduce the crash myself (at least on Win11, didn't try Win10 yet). However, if there is a D3Dll mutex being used, it seems that having the app acquire and release it is a safe (and advisable) thing to do.

If you put more changes in places, I will give them a try.

Thanks.

[castorix]

ATM, my first tries with IDXGIKeyedMutex ... are a failure.
I did some tests from MSDN doc at https://learn.microsoft.com/en-us/windows/win32/direct3darticles/surface-sharing-between-windows-graphics-apis
but I get locks or black texture or crashes...

[rcohn]

I was shown a way to use System.Drawing.Graphics.CopyFromScreen(), which works quite well. I use that method to produce a System.Drawing.Bitmap, which I can then use with Bitmap.Save to produce a png format image file. I save the PNG to the user's temp space, from where I can read it back in and use to Source an image. There is probably a way to do that using a stream, which I will have to investigate when I get some time.

Anyway, this works fine for my needs. Thanks again for your help.

[castorix]

Yes, CopyFromScreen is the old GDI method with BitBlt(), that can work for most cases

[khoabui1412]

I'm trying to use GraphicsCaptureItem to capture screen but: GraphicsCaptureItem.TryCreateFromWindowId only supports on win11.
I use this instead:

        static readonly Guid GraphicsCaptureItemGuid = new Guid("79C3F95B-31F7-4EC2-A464-632EF5D30760");
        [ComImport]
        [Guid("3628E81B-3CAC-4C60-B7F4-23CE0E0C3356")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        [ComVisible(true)]
        interface IGraphicsCaptureItemInterop
        {
            IntPtr CreateForWindow(
                [In] IntPtr window,
                [In] ref Guid iid);

            IntPtr CreateForMonitor(
                [In] IntPtr monitor,
                [In] ref Guid iid);
        }
        public static GraphicsCaptureItem CreateItemForWindow(IntPtr hwnd)
       {
            var interop = GraphicsCaptureItem.As<IGraphicsCaptureItemInterop>();
            var itemPointer = interop.CreateForWindow(hwnd, GraphicsCaptureItemGuid);
            var item = Marshal.GetObjectForIUnknown(itemPointer) as GraphicsCaptureItem;
            Marshal.Release(itemPointer);
            return item:
       }

But the item is null, am I missing something? is it possibile on win10? Thanks

[castorix]

is it possibile on win10?

If you only want to capture screen, you can just use GDI (a simple BitBlt for example) or to capture a window, PrintWindow to a memory DC (with PW_RENDERFULLCONTENT flag)

[MathewRimmington]

I had the same problem, not sure if you ever resolved this, I implemented this myself swapping line
var item = Marshal.GetObjectForIUnknown(itemPointer) as GraphicsCaptureItem;

with
var item = WinRT.MarshalInterface<GraphicsCaptureItem>.FromAbi(itemPointer);

[castorix]

MathewRimmington
2 days ago
I had the same problem, not sure if you ever resolved this, I implemented this myself swapping line
var item = Marshal.GetObjectForIUnknown(itemPointer) as GraphicsCaptureItem;
with
var item = WinRT.MarshalInterface.FromAbi(itemPointer);

It works on my configuration (Windows 10 22H2, Windows App SDK 1.4.2)

[castorix]

I quickly tested all the methods and Desktop Duplication (IDXGIOutputDuplication::AcquireNextFrame) converted to a WriteableBitmap works fine (better than BitBlt which cannot capture DirectX)
I could upload a test sample if you cannot make GraphicsCaptureItem work (I also get a null value from Marshal.GetObjectForIUnknown on Windows 10 21H1)

[sigmarsson]

Could you share the snippet, which is working on 10 and/or 11 ? Merci!