Check for API availability on older Windows versions

[mightypanda]

Hello, What is the correct way to check for availability of the screen-capture API? A check on windows version or expecting an exception? Thank you!

[robmikh]

Assuming you're at least on the very first version of Windows 10, you'll first need to check that the capture API itself is available. You can do that with the ApiInformation.IsTypePresent function. Next you'll want to make sure that screen capture is supported on the device you're on (e.g. the Xbox does not support screen capture via Windows.Graphics.Capture at this time), which you can do with GraphicsCaptureSession.IsSupported. That'll look something like this:

auto supported = 
    winrt::Windows::Foundation::Metadata::ApiInformation::IsTypePresent(
        L"Windows.Graphics.Capture.GraphicsCaptureSession") 
    && 
    winrt::Windows::Graphics::Capture::GraphicsCaptureSession::IsSupported();

That's the minimum for using the GraphicsCapturePicker object to select a GraphicsCaptureItem to capture. However, if you'd like to use the IGraphicsCaptureItemInterop interface to capture a window or monitor using a HWND or HMONITOR respectively, you'll need to either check for the interface on the GraphicsCaptureItem factory or check for UniversalApiContract v8:

auto isWin32ProgrammaticPresent = 
    winrt::ApiInformation::IsApiContractPresent(L"Windows.Foundation.UniversalApiContract", 8);

See issue #50 for more discussion on this topic, as well as how to check for certain features that were introduced later on (e.g. the IsCursorCaptureEnabled property).

[robmikh]

Closing this for now, but feel free to ask more questions!