为什么 ID3D11DeviceContext::map() 函数不起作用并返回 E_INVALIDAGR（一个或多个参数无效）

Question

当我想使用 DXGI Duplication API 截图时，deviceContext->map() 总是失败。它返回E_INVALIDAGR（一个或多个参数无效）。不过，我认为没有任何论据是无效的。我不知道如何解决这个问题。这是我的代码。 （所有初始化均成功，包括device、deviceContext、dxgiOutputDuplication）。

/*
this function take a screenshot and save the bmp image of the screenshot to the data pointer.
@param BYTE* data: (out) The pointer to a BYTE array where the bmp image will be saved to.
@return ULARGE_INTEGER: the size of bmp image.
*/
ULARGE_INTEGER GetFrame(BYTE* data) {

    IDXGIResource* desktopResource = nullptr;
    DXGI_OUTDUPL_FRAME_INFO FrameInfo{};
    ID3D11Texture2D* acquiredDesktopImage = nullptr;
    
    //Get new frame
    HRESULT hr = 0;
    do {
        hr = dxgiOutputDuplication->AcquireNextFrame(1000, &FrameInfo, &desktopResource);
    } while (hr != S_OK);
    

    hr = desktopResource->QueryInterface(__uuidof(ID3D11Texture2D), reinterpret_cast<void**>(&acquiredDesktopImage));
    if (hr != S_OK) {
    printf("failed to query interface\n");
    }
    D3D11_MAPPED_SUBRESOURCE* resource = new D3D11_MAPPED_SUBRESOURCE();

    ID3D11Texture2D* copiedImage = nullptr;

    D3D11_TEXTURE2D_DESC desc{};

    acquiredDesktopImage->GetDesc(&desc);

    desc.Usage = D3D11_USAGE_DEFAULT;
    desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
    desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;

    hr = device->CreateTexture2D(&desc, NULL, &copiedImage);
    if (hr != S_OK) {
    printf("failed to create texture\n");
    }
    deviceContext->CopyResource(copiedImage, acquiredDesktopImage);
    
    hr = deviceContext->Map(copiedImage, 0, D3D11_MAP_READ, NULL, resource);  
    // always failed in the upper line.
    
    if (hr != S_OK) {
    printf("failed to map\n");
    }

    
    ULARGE_INTEGER length = encodeData(dxgiOutDuplDesc.ModeDesc.Width, dxgiOutDuplDesc.ModeDesc.Height, resource->RowPitch, resource->pData, data);
    // This function is to encode the data from rgb matrix to bmp format. 
    // Here is the description of this function.
    /*
    encode RGB matrix to bmp format and save it into data
    @param int width: (in) matrix width
    @param int height: (in) matrix height
    @param UINT stride: (in) the size of a line of matrix
    @param void* pixels: (in) data source pointer
    @param BYTE* data: (out) data result pointer
    @return ULARGE_INTEGER: data result length
    */

    desktopResource->Release();
    acquiredDesktopImage->Release();
    delete resource;
    return length;
}

这是初始化函数。

BOOL initDevice() {
    IDXGIDevice*            dxgiDevice = nullptr;
    IDXGIAdapter*           dxgiAdapter = nullptr;
    IDXGIOutput*            dxgiOutput = nullptr;
    IDXGIOutput1*           dxgiOutput1 = nullptr;

    D3D_FEATURE_LEVEL feature_levels[] = {
        D3D_FEATURE_LEVEL_11_0
    };

    CHECK_RESULT(D3D11CreateDevice(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, D3D11_CREATE_DEVICE_DEBUG, feature_levels, ARRAYSIZE(feature_levels), D3D11_SDK_VERSION, &device, NULL, &deviceContext));
    printf("successful init create d3d11 device\n");

    // Get DXGI device
    CHECK_RESULT(device->QueryInterface(__uuidof(IDXGIDevice), reinterpret_cast<void**>(&dxgiDevice)));

    // Get DXGI adapter
    CHECK_RESULT(dxgiDevice->GetParent(__uuidof(IDXGIAdapter), reinterpret_cast<void**>(&dxgiAdapter)));


    // Get output
    CHECK_RESULT(dxgiAdapter->EnumOutputs(0, &dxgiOutput));


    CHECK_RESULT(dxgiOutput->GetDesc(&dxgiOutputDesc));

    // QI for Output 1
    CHECK_RESULT(dxgiOutput->QueryInterface(__uuidof(dxgiOutput1), reinterpret_cast<void**>(&dxgiOutput1)));
    

    // Create desktop duplication
    CHECK_RESULT(dxgiOutput1->DuplicateOutput(device, &dxgiOutputDuplication));

    dxgiOutputDuplication->GetDesc(&dxgiOutDuplDesc);

    dxgiDevice->Release();
    dxgiDevice = nullptr;
    dxgiAdapter->Release();
    dxgiAdapter = nullptr;
    dxgiOutput->Release();
    dxgiOutput = nullptr;
    dxgiOutput1->Release();
    dxgiOutput1 = nullptr;
    return true;
}

这是我使用的宏。

#define CHECK_RESULT(func) if ((func) != S_OK) return false

我尝试更改desc(D3D11_TEXTURE2D_DESC)的几乎所有参数，但都无法成功。另外，我搜索过这个问题，他们文章上的代码和我的一样，所以我对发生的事情感到非常困惑。有人能帮我吗？我将非常感谢你的帮助。

Answer 1

您的“copiedImage”纹理对于映射无效：

desc.Usage = D3D11_USAGE_DEFAULT;
desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;

应该类似于：

desc.Usage = D3D11_USAGE_STAGING;
desc.BindFlags = 0;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;

看看这个 ScreenGrab 代码。

您也没有释放您的 copiedImage 纹理。您应该考虑使用 COM 智能指针，例如 Microsoft::WRL::ComPtr避免资源泄漏。

请注意，对于 DirectX 11.1 或更高版本，有一个可选硬件功能支持在 D3D11_USAGE_DEFAULT 资源上调用 Map，但它只能工作如果驱动程序将 D3D11_FEATURE_DATA_D3D11_OPTIONS1.MapOnDefaultBuffers 报告为 TRUE -并且 - 您正在使用ID3D11Buffer。这对纹理永远不起作用。