C++/WinRT：MCVC 不链接事件回调

Question

我正在尝试在 C++ 项目中使用 Desktop Capture API。

这里是帧池的初始化：

ScreenGrabWinCaptureApi::ScreenGrabWinCaptureApi() {
    //
    // <neccessary stuff for d3d device and capture item creation>
    //

    framePool = winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool::CreateFreeThreaded(d3dDevice2,
                                                                                                  winrt::Windows::Graphics::DirectX::DirectXPixelFormat::B8G8R8A8UIntNormalized,
                                                                                                  2, item.Size());
    framePool.FrameArrived(&ScreenGrabWinCaptureApi::OnFrameArrived);
    captureSession = framePool.CreateCaptureSession(item);
    captureSession.StartCapture();
}

这里是 ScreenGrabWinCaptureApi::OnFrameArrived 定义：

void
ScreenGrabWinCaptureApi::OnFrameArrived(const winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool &sender,
                                        const winrt::Windows::Foundation::IInspectable &) {
    // <some buisness logic>
}

我正在尝试构建它，代码对编译器来说似乎没问题，但是在 framePool.FrameArrived(&ScreenGrabWinCaptureApi::OnFrameArrived); 调用

时链接失败

error LNK2019: unresolved external symbol "public: __cdecl winrt::Windows::Foundation::TypedEventHandler<struct winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool,struct winrt::Windows::Foundation::IInspectable>::TypedEventHandler<struct winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool,struct winrt::Windows::Foundation::IInspectable><void (__cdecl ScreenGrabWinCaptureApi::)(struct winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool const &,struct winrt::Windows::Foundation::IInspectable const &)>(void (__cdecl ScreenGrabWinCaptureApi::)(struct winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool const &,struct winrt::Windows::Foundation::IInspectable const &))" (??$?0P8ScreenGrabWinCaptureApi@@EAAXAEBUDirect3D11CaptureFramePool@Capture@Graphics@Windows@winrt@@AEBUIInspectable@Foundation@45@@Z@?$TypedEventHandler@UDirect3D11CaptureFramePool@Capture@Graphics@Windows@winrt@@UIInspectable@Foundation@45@@Foundation@Windows@winrt@@QEAA@P8ScreenGrabWinCaptureApi@@EAAXAEBUDirect3D11CaptureFramePool@Capture@Graphics@23@AEBUIInspectable@123@@Z@Z) referenced in function "public: __cdecl ScreenGrabWinCaptureApi::ScreenGrabWinCaptureApi(void)" (??0ScreenGrabWinCaptureApi@@QEAA@XZ)

我已经尝试了所有 reinterpret/static 转换方式，用方法引用引入变量，用 clojure 替换方法，但没有任何效果。任何人都知道这是什么原因以及如何做到这一点运行?

Answer 1

正如 Simon Mourier 在评论中所说，我忘记将 header 添加到 TypedEventHandler。我的代码在插入相应的 include 后工作：

#include "winrt/Windows.Foundation.h"

C++/WinRT：MCVC 不链接事件回调

C++/WinRT: MCVC doesn't linking event callback

linker

windows-runtime

c++-winrt