win32

该代码来源于codeproject，经过测试发现，在屏幕处于旋转的情况下捕获的图像是黑色的。暂时没有找到原因。

代码开箱即用，

#define WIN32_LEAN_AND_MEAN    

#include <windows.h>
#include <shlobj.h>
#include <shellapi.h>
#include <dxgi1_2.h>
#include <d3d11.h>
#include <memory>
#include <algorithm>
#include <string>

#pragma comment(lib, "D3D11.lib")

template <typename T>
class CComPtrCustom
{
public:

    CComPtrCustom(T *aPtrElement)
        :element(aPtrElement)
    {
    }

    CComPtrCustom()
        :element(nullptr)
    {
    }

    virtual ~CComPtrCustom()
    {
        Release();
    }

    T* Detach()
    {
        auto lOutPtr = element;

        element = nullptr;

        return lOutPtr;
    }

    T* detach()
    {
        return Detach();
    }

    void Release()
    {
        if (element == nullptr)
            return;

        auto k = element->Release();

        element = nullptr;
    }

    CComPtrCustom& operator = (T *pElement)
    {
        Release();

        if (pElement == nullptr)
            return *this;

        auto k = pElement->AddRef();

        element = pElement;

        return *this;
    }

    void Swap(CComPtrCustom& other)
    {
        T* pTemp = element;
        element = other.element;
        other.element = pTemp;
    }

    T* operator->()
    {
        return element;
    }

    operator T*()
    {
        return element;
    }

    operator T*() const
    {
        return element;
    }


    T* get()
    {
        return element;
    }

    T* get() const
    {
        return element;
    }

    T** operator &()
    {
        return &element;
    }

    bool operator !()const
    {
        return element == nullptr;
    }

    operator bool()const
    {
        return element != nullptr;
    }

    bool operator == (const T *pElement)const
    {
        return element == pElement;
    }


    CComPtrCustom(const CComPtrCustom& aCComPtrCustom)
    {
        if (aCComPtrCustom.operator!())
        {
            element = nullptr;

            return;
        }

        element = aCComPtrCustom;

        auto h = element->AddRef();

        h++;
    }

    CComPtrCustom& operator = (const CComPtrCustom& aCComPtrCustom)
    {
        Release();

        element = aCComPtrCustom;

        auto k = element->AddRef();

        return *this;
    }

    _Check_return_ HRESULT CopyTo(T** ppT) throw()
    {
        if (ppT == NULL)
            return E_POINTER;

        *ppT = element;

        if (element)
            element->AddRef();

        return S_OK;
    }

    HRESULT CoCreateInstance(const CLSID aCLSID)
    {
        T* lPtrTemp;

        auto lresult = ::CoCreateInstance(aCLSID, NULL, CLSCTX_INPROC, IID_PPV_ARGS(&lPtrTemp));

        if (SUCCEEDED(lresult))
        {
            if (lPtrTemp != nullptr)
            {
                Release();

                element = lPtrTemp;
            }

        }

        return lresult;
    }

protected:

    T* element;
};


// Driver types supported
D3D_DRIVER_TYPE gDriverTypes[] =
{
    D3D_DRIVER_TYPE_HARDWARE
};
UINT gNumDriverTypes = ARRAYSIZE(gDriverTypes);

// Feature levels supported
D3D_FEATURE_LEVEL gFeatureLevels[] =
{
    D3D_FEATURE_LEVEL_11_0,
    D3D_FEATURE_LEVEL_10_1,
    D3D_FEATURE_LEVEL_10_0,
    D3D_FEATURE_LEVEL_9_1
};

UINT gNumFeatureLevels = ARRAYSIZE(gFeatureLevels);


int main()
{
    CComPtrCustom<ID3D11Device> lDevice;
    CComPtrCustom<ID3D11DeviceContext> lImmediateContext;
    CComPtrCustom<IDXGIOutputDuplication> lDeskDupl;
    CComPtrCustom<ID3D11Texture2D> lAcquiredDesktopImage;
    CComPtrCustom<ID3D11Texture2D> lGDIImage;
    CComPtrCustom<ID3D11Texture2D> lDestImage;
    DXGI_OUTPUT_DESC lOutputDesc;
    DXGI_OUTDUPL_DESC lOutputDuplDesc;

    int lresult(-1);

    do
    {

        

        D3D_FEATURE_LEVEL lFeatureLevel;

        HRESULT hr(E_FAIL);

        // Create device
        for (UINT DriverTypeIndex = 0; DriverTypeIndex < gNumDriverTypes; ++DriverTypeIndex)
        {
            hr = D3D11CreateDevice(
                nullptr,
                gDriverTypes[DriverTypeIndex],
                nullptr,
                0,
                gFeatureLevels,
                gNumFeatureLevels,
                D3D11_SDK_VERSION,
                &lDevice,
                &lFeatureLevel,
                &lImmediateContext);

            if (SUCCEEDED(hr))
            {
                // Device creation success, no need to loop anymore
                break;
            }

            lDevice.Release();

            lImmediateContext.Release();
        }

        if (FAILED(hr))
            break;

        Sleep(100);

        if (lDevice == nullptr)
            break;
        
        // Get DXGI device
        CComPtrCustom<IDXGIDevice> lDxgiDevice;

        hr = lDevice->QueryInterface(IID_PPV_ARGS(&lDxgiDevice));

        if (FAILED(hr))
            break;

        // Get DXGI adapter
        CComPtrCustom<IDXGIAdapter> lDxgiAdapter;
        hr = lDxgiDevice->GetParent(
            __uuidof(IDXGIAdapter),
            reinterpret_cast<void**>(&lDxgiAdapter));

        if (FAILED(hr))
            break;

        lDxgiDevice.Release();

        UINT Output = 0;

        // Get output
        CComPtrCustom<IDXGIOutput> lDxgiOutput;
        hr = lDxgiAdapter->EnumOutputs(
            Output,
            &lDxgiOutput);

        if (FAILED(hr))
            break;

        lDxgiAdapter.Release();

        hr = lDxgiOutput->GetDesc(
            &lOutputDesc);

        if (FAILED(hr))
            break;

        // QI for Output 1
        CComPtrCustom<IDXGIOutput1> lDxgiOutput1;

        hr = lDxgiOutput->QueryInterface(IID_PPV_ARGS(&lDxgiOutput1));

        if (FAILED(hr))
            break;

        lDxgiOutput.Release();

        // Create desktop duplication
        hr = lDxgiOutput1->DuplicateOutput(
            lDevice,
            &lDeskDupl);

        if (FAILED(hr))
            break;

        lDxgiOutput1.Release();

        // Create GUI drawing texture
        lDeskDupl->GetDesc(&lOutputDuplDesc);

        D3D11_TEXTURE2D_DESC desc;

        desc.Width = lOutputDuplDesc.ModeDesc.Width;

        desc.Height = lOutputDuplDesc.ModeDesc.Height;

        desc.Format = lOutputDuplDesc.ModeDesc.Format;

        desc.ArraySize = 1;

        desc.BindFlags = D3D11_BIND_FLAG::D3D11_BIND_RENDER_TARGET;

        desc.MiscFlags = D3D11_RESOURCE_MISC_GDI_COMPATIBLE;

        desc.SampleDesc.Count = 1;

        desc.SampleDesc.Quality = 0;

        desc.MipLevels = 1;

        desc.CPUAccessFlags = 0;

        desc.Usage = D3D11_USAGE_DEFAULT;

        hr = lDevice->CreateTexture2D(&desc, NULL, &lGDIImage);

        if (FAILED(hr))
            break;

        if (lGDIImage == nullptr)
            break;                    


        // Create CPU access texture

        desc.Width = lOutputDuplDesc.ModeDesc.Width;

        desc.Height = lOutputDuplDesc.ModeDesc.Height;

        desc.Format = lOutputDuplDesc.ModeDesc.Format;

        desc.ArraySize = 1;

        desc.BindFlags = 0;

        desc.MiscFlags = 0;

        desc.SampleDesc.Count = 1;

        desc.SampleDesc.Quality = 0;

        desc.MipLevels = 1;

        desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ | D3D11_CPU_ACCESS_WRITE;
        desc.Usage = D3D11_USAGE_STAGING;

        hr = lDevice->CreateTexture2D(&desc, NULL, &lDestImage);

        if (FAILED(hr))
            break;

        if (lDestImage == nullptr)
            break;

        CComPtrCustom<IDXGIResource> lDesktopResource;
        DXGI_OUTDUPL_FRAME_INFO lFrameInfo;

        int lTryCount = 4;

        do
        {

            Sleep(100);

            // Get new frame
            hr = lDeskDupl->AcquireNextFrame(
                250,
                &lFrameInfo,
                &lDesktopResource);
            
            if (SUCCEEDED(hr))
                break;

            if (hr == DXGI_ERROR_WAIT_TIMEOUT)
            {
                continue;
            }
            else if (FAILED(hr))
                break;            

        } while (--lTryCount > 0);

        if (FAILED(hr))
            break;

        // QI for ID3D11Texture2D

        hr = lDesktopResource->QueryInterface(IID_PPV_ARGS(&lAcquiredDesktopImage));

        if (FAILED(hr))
            break;

        lDesktopResource.Release();

        if (lAcquiredDesktopImage == nullptr)
            break;
                
        // Copy image into GDI drawing texture

        lImmediateContext->CopyResource(lGDIImage, lAcquiredDesktopImage);
        

        // Draw cursor image into GDI drawing texture

        CComPtrCustom<IDXGISurface1> lIDXGISurface1;
        
        hr = lGDIImage->QueryInterface(IID_PPV_ARGS(&lIDXGISurface1));

        if (FAILED(hr))
            break;

        CURSORINFO lCursorInfo = { 0 };

        lCursorInfo.cbSize = sizeof(lCursorInfo);

        auto lBoolres = GetCursorInfo(&lCursorInfo);

        if (lBoolres == TRUE)
        {
            if (lCursorInfo.flags == CURSOR_SHOWING)
            {
                auto lCursorPosition = lCursorInfo.ptScreenPos;

                auto lCursorSize = lCursorInfo.cbSize;

                HDC  lHDC;

                lIDXGISurface1->GetDC(FALSE, &lHDC);

                DrawIconEx(
                    lHDC,
                    lCursorPosition.x,
                    lCursorPosition.y,
                    lCursorInfo.hCursor,
                    0,
                    0,
                    0,
                    0,
                    DI_NORMAL | DI_DEFAULTSIZE);

                lIDXGISurface1->ReleaseDC(nullptr);
            }

        }

        // Copy image into CPU access texture

        lImmediateContext->CopyResource(lDestImage, lGDIImage);
        

        // Copy from CPU access texture to bitmap buffer

        D3D11_MAPPED_SUBRESOURCE resource;
        UINT subresource = D3D11CalcSubresource(0, 0, 0);
        lImmediateContext->Map(lDestImage, subresource, D3D11_MAP_READ_WRITE, 0, &resource);
        
        BITMAPINFO    lBmpInfo;

        // BMP 32 bpp

        ZeroMemory(&lBmpInfo, sizeof(BITMAPINFO));

        lBmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

        lBmpInfo.bmiHeader.biBitCount = 32;

        lBmpInfo.bmiHeader.biCompression = BI_RGB;

        lBmpInfo.bmiHeader.biWidth = lOutputDuplDesc.ModeDesc.Width;

        lBmpInfo.bmiHeader.biHeight = lOutputDuplDesc.ModeDesc.Height;

        lBmpInfo.bmiHeader.biPlanes = 1;
    
        lBmpInfo.bmiHeader.biSizeImage = lOutputDuplDesc.ModeDesc.Width 
            * lOutputDuplDesc.ModeDesc.Height * 4;


        std::unique_ptr<BYTE> pBuf(new BYTE[lBmpInfo.bmiHeader.biSizeImage]);


        UINT lBmpRowPitch = lOutputDuplDesc.ModeDesc.Width * 4;

        BYTE* sptr = reinterpret_cast<BYTE*>(resource.pData);
        BYTE* dptr = pBuf.get() + lBmpInfo.bmiHeader.biSizeImage - lBmpRowPitch;

        UINT lRowPitch = std::min<UINT>(lBmpRowPitch, resource.RowPitch);


        for (size_t h = 0; h < lOutputDuplDesc.ModeDesc.Height; ++h)
        {
            
            memcpy_s(dptr, lBmpRowPitch, sptr, lRowPitch);
            sptr += resource.RowPitch;
            dptr -= lBmpRowPitch;
        }

        // Save bitmap buffer into the file ScreenShot.bmp

        WCHAR lMyDocPath[MAX_PATH];

        hr = SHGetFolderPath(nullptr, CSIDL_PERSONAL, nullptr, SHGFP_TYPE_CURRENT, lMyDocPath);

        if (FAILED(hr))
            break;

        std::wstring lFilePath = std::wstring(lMyDocPath) + L"\ScreenShot.bmp";



        FILE* lfile = nullptr;

        auto lerr = _wfopen_s(&lfile, lFilePath.c_str(), L"wb");

        if (lerr != 0)
            break;

        if (lfile != nullptr)
        {

            BITMAPFILEHEADER    bmpFileHeader;

            bmpFileHeader.bfReserved1 = 0;
            bmpFileHeader.bfReserved2 = 0;
            bmpFileHeader.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + lBmpInfo.bmiHeader.biSizeImage;
            bmpFileHeader.bfType = 'MB';
            bmpFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

            fwrite(&bmpFileHeader, sizeof(BITMAPFILEHEADER), 1, lfile);
            fwrite(&lBmpInfo.bmiHeader, sizeof(BITMAPINFOHEADER), 1, lfile);
            fwrite(pBuf.get(), lBmpInfo.bmiHeader.biSizeImage, 1, lfile);

            fclose(lfile);

            ShellExecute(0, 0, lFilePath.c_str(), 0, 0, SW_SHOW);

            lresult = 0;
            
        }
        
    } while (false);
    
    return lresult;
}

如果需要录屏，可以参考另一个文章：screen-recorder