使用C++和Direct3D (d3d)获取屏幕截图并根据传入分辨率进行缩放图片大小(最新推荐)

这里提供一个使用C++和Direct3D (d3d)获取屏幕截图并根据传入分辨率进行缩放图片大小的攻略，具体步骤如下：

步骤1：初始化Direct3D

使用Direct3D获取屏幕截图需要初始化Direct3D，示例代码如下：

// 引入Direct3D
#include <d3d9.h>
#pragma comment(lib, "d3d9.lib")

IDirect3D9Ex* pD3D = NULL;
IDirect3DDevice9Ex* pDevice = NULL;

// 初始化Direct3D
HRESULT hr = S_OK;
hr = Direct3DCreate9Ex(D3D_SDK_VERSION, &pD3D);

// 创建Direct3D设备
D3DPRESENT_PARAMETERS d3dpp = { 0 };
d3dpp.Windowed = TRUE;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
hr = pD3D->CreateDeviceEx(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, NULL,
                          D3DCREATE_HARDWARE_VERTEXPROCESSING | D3DCREATE_FPU_PRESERVE,
                          &d3dpp, NULL, &pDevice);

步骤2：获取屏幕大小

获取屏幕大小，示例代码如下：

int screen_width = GetSystemMetrics(SM_CXSCREEN);
int screen_height = GetSystemMetrics(SM_CYSCREEN);

步骤3：创建Direct3D表面

创建Direct3D表面，示例代码如下：

IDirect3DSurface9* pSurface = NULL;
hr = pDevice->CreateOffscreenPlainSurface(screen_width, screen_height, D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM, &pSurface, NULL);

步骤4：获取前台图案

获取前台图案，示例代码如下：

hr = pDevice->GetFrontBufferData(0, pSurface);

步骤5：创建缩放表面

创建缩放表面，示例代码如下：

unsigned int scaled_width = 800;  // 缩放后的宽度
unsigned int scaled_height = 600; // 缩放后的高度

IDirect3DSurface9* pScaledSurface = NULL;
hr = pDevice->CreateOffscreenPlainSurface(scaled_width, scaled_height, D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM, &pScaledSurface, NULL);

步骤6：缩放图像

缩放图像，示例代码如下：

D3DXLoadSurfaceFromSurface(pScaledSurface, NULL, NULL, pSurface, NULL, NULL, D3DX_DEFAULT, 0);

步骤7：保存图像

保存图像，示例代码如下：

LPDIRECT3DTEXTURE9 pTexture = NULL;
hr = D3DXCreateTextureFromFileEx(pDevice, L"result.png", D3DX_DEFAULT, D3DX_DEFAULT, D3DX_DEFAULT, 0, 
                                  D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, D3DX_FILTER_NONE, D3DX_FILTER_NONE, 0, NULL, NULL, &pTexture);
D3DXSaveTextureToFile(L"result.png", D3DXIFF_PNG, pTexture, NULL);

这样就可以获取屏幕截图并根据传入分辨率进行缩放图片大小了。

下面是一个完整的例子：

#include <Windows.h>
#include <d3d9.h>
#include <d3dx9.h>
#pragma comment(lib, "d3d9.lib")
#pragma comment(lib, "d3dx9.lib")

int main(int argc, char** argv)
{
    HRESULT hr = S_OK;
    IDirect3D9Ex* pD3D = NULL;
    IDirect3DDevice9Ex* pDevice = NULL;

    // 初始化Direct3D
    hr = Direct3DCreate9Ex(D3D_SDK_VERSION, &pD3D);

    // 创建Direct3D设备
    D3DPRESENT_PARAMETERS d3dpp = { 0 };
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    hr = pD3D->CreateDeviceEx(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, NULL,
                              D3DCREATE_HARDWARE_VERTEXPROCESSING | D3DCREATE_FPU_PRESERVE,
                              &d3dpp, NULL, &pDevice);

    // 获取屏幕大小
    int screen_width = GetSystemMetrics(SM_CXSCREEN);
    int screen_height = GetSystemMetrics(SM_CYSCREEN);

    // 创建Direct3D表面
    IDirect3DSurface9* pSurface = NULL;
    hr = pDevice->CreateOffscreenPlainSurface(screen_width, screen_height, D3DFMT_A8R8G8B8, 
                                               D3DPOOL_SYSTEMMEM, &pSurface, NULL);

    // 获取前台图案
    hr = pDevice->GetFrontBufferData(0, pSurface);

    // 创建缩放表面
    unsigned int scaled_width = 800;  // 缩放后的宽度
    unsigned int scaled_height = 600; // 缩放后的高度
    IDirect3DSurface9* pScaledSurface = NULL;
    hr = pDevice->CreateOffscreenPlainSurface(scaled_width, scaled_height, D3DFMT_A8R8G8B8, 
                                               D3DPOOL_SYSTEMMEM, &pScaledSurface, NULL);

    // 缩放图像
    D3DXLoadSurfaceFromSurface(pScaledSurface, NULL, NULL, pSurface, NULL, NULL, D3DX_DEFAULT, 0);

    // 保存图像
    LPDIRECT3DTEXTURE9 pTexture = NULL;
    hr = D3DXCreateTextureFromFileEx(pDevice, L"result.png", D3DX_DEFAULT, D3DX_DEFAULT, D3DX_DEFAULT, 
                                     0, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, D3DX_FILTER_NONE, 
                                     D3DX_FILTER_NONE, 0, NULL, NULL, &pTexture);
    hr = D3DXSaveTextureToFile(L"result.png", D3DXIFF_PNG, pTexture, NULL);

    // 释放资源
    pSurface->Release();
    pScaledSurface->Release();
    pDevice->Release();
    pD3D->Release();

    return 0;
}

该示例只是抓取了一张图像，并进行了缩放和保存到本地磁盘，读者可以根据自己的需要进行扩展。