Somthing is wrong with Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes (not straight forward to call it)

[cosmin42]

I managed to isolate this problem into a simple project: https://github.com/cosmin42/Win2DIssue

Using the CreateFromBytes static method in the below function seems to be impossible to build as it asks for array_view when passing IBuffer and then asking for array_view when passing IBuffer.

void CanvasControlDraw([[maybe_unused]] winrt::Microsoft::Graphics::Canvas::
    UI::Xaml::CanvasControl const& sender,
    [[maybe_unused]] winrt::Microsoft::Graphics::Canvas::
    UI::Xaml::CanvasDrawEventArgs const& args)
{
    auto session = args.DrawingSession();

    Microsoft::Graphics::Canvas::CanvasDevice device =
        Microsoft::Graphics::Canvas::CanvasDevice::GetSharedDevice();

    winrt::array_view<uint8_t const> view_name;

    const auto format = Microsoft::Graphics::DirectX::DirectXPixelFormat::
        B8G8R8A8UIntNormalized;
    auto const& f2 = format;

    winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator const& resource =
        device;

    winrt::Windows::Storage::Streams::IBuffer buffer;
    Microsoft::Graphics::Canvas::CanvasBitmap bitmap =
        Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(
            resource, view_name, (int32_t)3,
            (int32_t)3, f2);

    session.DrawImage(bitmap);
}

The build error:

1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): error C2665: 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes': no overloaded function could convert all the argument types (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\Generated Files\winrt\Microsoft.Graphics.Canvas.h(4284,31): message : could be 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,const winrt::Windows::Storage::Streams::IBuffer &,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,const winrt::Windows::Storage::Streams::IBuffer &,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)': cannot convert argument 2 from 'winrt::array_view<const uint8_t>' to 'const winrt::Windows::Storage::Streams::IBuffer &' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(47,31): message : Reason: cannot convert from 'winrt::array_view<const uint8_t>' to 'const winrt::Windows::Storage::Streams::IBuffer' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(47,31): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\Generated Files\winrt\Microsoft.Graphics.Canvas.h(4272,31): message : or       'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,winrt::array_view<const uint8_t>,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,winrt::array_view<const uint8_t>,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)': cannot convert argument 5 from 'const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat' to 'const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(48,33): message : Reason: cannot convert from 'const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat' to 'const winrt::Windows::Graphics::DirectX::DirectXPixelFormat' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(48,33): message : Conversion to enumeration type requires an explicit cast (static_cast, C-style cast or parenthesized function-style cast) (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : while trying to match the argument list '(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator, winrt::array_view<const uint8_t>, int, int, const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat)' (compiling source file MainWindow.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): error C2665: 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes': no overloaded function could convert all the argument types (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\Generated Files\winrt\Microsoft.Graphics.Canvas.h(4284,31): message : could be 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,const winrt::Windows::Storage::Streams::IBuffer &,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,const winrt::Windows::Storage::Streams::IBuffer &,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)': cannot convert argument 2 from 'winrt::array_view<const uint8_t>' to 'const winrt::Windows::Storage::Streams::IBuffer &' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(47,31): message : Reason: cannot convert from 'winrt::array_view<const uint8_t>' to 'const winrt::Windows::Storage::Streams::IBuffer' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(47,31): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\Generated Files\winrt\Microsoft.Graphics.Canvas.h(4272,31): message : or       'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,winrt::array_view<const uint8_t>,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : 'winrt::Microsoft::Graphics::Canvas::CanvasBitmap winrt::Microsoft::Graphics::Canvas::CanvasBitmap::CreateFromBytes(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator &,winrt::array_view<const uint8_t>,int32_t,int32_t,const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &)': cannot convert argument 5 from 'const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat' to 'const winrt::Windows::Graphics::DirectX::DirectXPixelFormat &' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(48,33): message : Reason: cannot convert from 'const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat' to 'const winrt::Windows::Graphics::DirectX::DirectXPixelFormat' (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(48,33): message : Conversion to enumeration type requires an explicit cast (static_cast, C-style cast or parenthesized function-style cast) (compiling source file App.xaml.cpp)
1>C:\Users\user\Win2DIssue\Example\MainWindow.xaml.h(46,60): message : while trying to match the argument list '(const winrt::Microsoft::Graphics::Canvas::ICanvasResourceCreator, winrt::array_view<const uint8_t>, int, int, const winrt::Microsoft::Graphics::DirectX::DirectXPixelFormat)' (compiling source file App.xaml.cpp)

Any idea why the polymorphism seems to fail in this case? The functions seem to be correctly defined under Microsoft.Graphics.Canvas.h .

The workaround is to convert explicitly format to (winrt::Windows::Graphics::DirectX::DirectXPixelFormat const&) when calling the function.