directx - 使用 DirectX 的桌面捕获不起作用

Question

由于D3DPOOL_SCRATCH处理速度较慢，所以我编写了桌面捕获程序以引用网上的报告。然而，结果却是一片漆黑的画面。这是控制台程序的结果还是有其他原因？

#include <stdio.h>
#include <Windows.h>
#include <d3d9.h>

void main()
{
    CoInitialize(NULL);

    LPDIRECT3D9 d3d9;
    LPDIRECT3DDEVICE9 d3ddev;
    d3d9 = Direct3DCreate9(D3D_SDK_VERSION);

    int ww = GetSystemMetrics(SM_CXSCREEN);
    int wh = GetSystemMetrics(SM_CYSCREEN);

    HWND hwnd = GetDesktopWindow();
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
    d3dpp.BackBufferCount = 1;
    d3dpp.BackBufferWidth = ww;
    d3dpp.BackBufferHeight = wh;
    d3dpp.MultiSampleType = D3DMULTISAMPLE_NONE;
    d3dpp.MultiSampleQuality = 0;
    d3dpp.EnableAutoDepthStencil = TRUE;
    d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
    d3dpp.hDeviceWindow = hwnd;
    d3dpp.Flags = D3DPRESENTFLAG_LOCKABLE_BACKBUFFER;
    d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT;
    d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_DEFAULT;

    d3d9->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &d3dpp, &d3ddev);

    IDirect3DSurface9* render;
    IDirect3DSurface9* dest;
    d3ddev->CreateOffscreenPlainSurface(ww, wh, D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM, &dest, NULL);
    d3ddev->GetRenderTarget(0, &render);
    d3ddev->GetRenderTargetData(render, dest);

    D3DLOCKED_RECT bits;
    dest->LockRect(&bits, NULL, D3DLOCK_READONLY);

    // If a capture is successful, colors other than black(0x00000000) should enter. 
    for(int i = 0; i < 100; i++){
        printf("%02X ", *((BYTE*)bits.pBits + i));
    }

    dest->UnlockRect();

    render->Release();
    dest->Release();
    d3ddev->Release();
    d3d9->Release();

    CoUninitialize();
}

Answer 1

这与应用程序类型无关，如果你想获取桌面图像的数据，你应该使用以下函数

GetFrontBufferData

所以不要打电话

d3ddev->GetRenderTarget(0, &render);
d3ddev->GetRenderTargetData(render, dest);

你应该打电话

d3ddev->GetFrontBufferData(0, dest);