Drectx 3D窗口后台截图

 //GDI与DX截屏API操作
 LPDIRECTDRAW        lpDD       = NULL;
 LPDIRECTDRAWSURFACE lpDDSPrime = NULL;
 LPDIRECTDRAWSURFACE lpDDSBack  = NULL;
 LPDIRECTDRAWSURFACE lpDDSGdi   = NULL;
 LPDIRECTDRAWSURFACE lpSurf     = NULL;

 DDSURFACEDESC DDSdesc;
 BOOL m_b24=TRUE;
 //rfbServerInitMsg m_scrinfo;
 RECT    m_bmrect;

 struct _BMInfo {
     BITMAPINFO bmi       ;
     BOOL       truecolour;
     RGBQUAD    cmap[] ;
 } m_bminfo; // 用来保存位图信息的结构

 int DX_Init() {// DirectX初始化。返回当前表面获取一张屏幕位图的存储空间大小
     HRESULT hr;

     // 初始化directX
     hr = DirectDrawCreate(, &lpDD, );
     if (FAILED(hr)) return FALSE;

     hr = lpDD->SetCooperativeLevel(NULL, DDSCL_NORMAL);
     if (FAILED(hr)) return FALSE;

     ZeroMemory(&DDSdesc, sizeof(DDSdesc));
     DDSdesc.dwSize  = sizeof(DDSdesc);
     DDSdesc.dwFlags = DDSD_CAPS;
     DDSdesc.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;
     hr = lpDD->CreateSurface(&DDSdesc, &lpDDSPrime, );
     if (FAILED(hr)) return FALSE;

     hr = lpDD->GetGDISurface(&lpDDSGdi);
     if (FAILED(hr)) return FALSE;

     ZeroMemory(&DDSdesc, sizeof(DDSdesc));
     DDSdesc.dwSize  = sizeof(DDSdesc);
     DDSdesc.dwFlags = DDSD_ALL;
     hr = lpDDSPrime->GetSurfaceDesc(&DDSdesc);
     if (FAILED(hr)) return FALSE;

     // 初始化位图信息
     if ((DDSdesc.dwFlags & DDSD_WIDTH) && (DDSdesc.dwFlags & DDSD_HEIGHT)) {
         m_bmrect.left = m_bmrect.top = ;
         m_bmrect.right = DDSdesc.dwWidth;
         m_bmrect.bottom = DDSdesc.dwHeight;
     } else return FALSE;

     m_bminfo.bmi.bmiHeader.biCompression = BI_RGB;//BI_BITFIELDS;
     m_bminfo.bmi.bmiHeader.biBitCount = DDSdesc.ddpfPixelFormat.dwRGBBitCount;

     // m_bminfo.truecolour = DDSdesc.ddpfPixelFormat.dwFlags & DDPF_RGB;
     if (m_bminfo.bmi.bmiHeader.biBitCount > )
         m_bminfo.truecolour = TRUE;
     else
         m_bminfo.truecolour = FALSE;

     ZeroMemory(&DDSdesc, sizeof(DDSdesc));
     DDSdesc.dwSize = sizeof(DDSdesc);
     DDSdesc.dwFlags = DDSD_CAPS | DDSD_HEIGHT |DDSD_WIDTH;
     DDSdesc.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
     DDSdesc.dwHeight = m_bmrect.bottom - m_bmrect.top;
     DDSdesc.dwWidth  = m_bmrect.right  - m_bmrect.left;
     hr = lpDD->CreateSurface(&DDSdesc, &lpDDSBack, );
     if (FAILED(hr)) return FALSE;
 //  hr = lpDDSPrime->QueryInterface( IID_IDirectDrawSurface3, (LPVOID *)&lpSurf);
 //  if (FAILED(hr)) return FALSE;

     switch (m_bminfo.bmi.bmiHeader.biBitCount) {
     case :
     case :
        // Update the bitmapinfo header
        m_b24 = TRUE;
        m_bminfo.bmi.bmiHeader.biSize = sizeof( BITMAPINFOHEADER );
        m_bminfo.bmi.bmiHeader.biWidth = ;
        m_bminfo.bmi.bmiHeader.biHeight = ;
        m_bminfo.bmi.bmiHeader.biPlanes = ;
 //     m_bminfo.bmi.bmiHeader.biBitCount = 24;
        m_bminfo.bmi.bmiHeader.biCompression = BI_RGB;
        m_bminfo.bmi.bmiHeader.biSizeImage = abs((m_bminfo.bmi.bmiHeader.biWidth * m_bminfo.bmi.bmiHeader.biHeight * m_bminfo.bmi.bmiHeader.biBitCount)/);
        m_bminfo.bmi.bmiHeader.biXPelsPerMeter = (*)/;
        m_bminfo.bmi.bmiHeader.biYPelsPerMeter = (*)/;
        m_bminfo.bmi.bmiHeader.biClrUsed   = ;
        m_bminfo.bmi.bmiHeader.biClrImportant = ;
        break;
     }

     return m_bminfo.bmi.bmiHeader.biSizeImage;
 }

 BOOL CaptureScreen(RECT &rect, BYTE *scrBuff, UINT scrBuffSize) {// 捕捉屏幕。rect: 区域。scrBuff: 输出缓冲。scrBuffSize: 缓冲区大小
     HRESULT hr=;

     hr = lpDDSBack->BltFast(rect.left,rect.top,lpDDSPrime,&rect,DDBLTFAST_NOCOLORKEY | DDBLTFAST_WAIT);
     if (FAILED(hr)) return FALSE;

     DDSURFACEDESC surfdesc;
     ZeroMemory(&surfdesc, sizeof(surfdesc));
     surfdesc.dwSize = sizeof(surfdesc);

     hr = lpDDSBack->Lock(&rect, &surfdesc, DDLOCK_READONLY | DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR /*|DDLOCK_NOSYSLOCK*/, NULL);
 //  hr = lpDDSPrime->Lock(&rect, &surfdesc, DDLOCK_READONLY | DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR /*|DDLOCK_NOSYSLOCK*/, NULL);
     if (FAILED(hr)) return FALSE;

     // copy the data into our buffer
     BYTE * destbuffpos, * srcbuffpos;
 //  m_scrinfo.format.bitsPerPixel = 24;
     srcbuffpos = (BYTE *) surfdesc.lpSurface;
     destbuffpos = scrBuff;

     memcpy( destbuffpos, srcbuffpos,m_bminfo.bmi.bmiHeader.biSizeImage);

     // unlock the primary surface
 //  lpDDSPrime->Unlock(surfdesc.lpSurface);
     lpDDSBack->Unlock(surfdesc.lpSurface);
     return TRUE;
 }

 int SaveBitmapToFile(BITMAP *bitmap, LPSTR lpFileName,char *lpBuf) {
    DWORD dwWritten;
    BITMAPFILEHEADER   bmfHdr;
    BITMAPINFOHEADER   bi;
    HANDLE          fh=NULL;
    bi.biSize = sizeof(BITMAPINFOHEADER);
    bi.biWidth= bitmap->bmWidth;
    bi.biHeight = bitmap->bmHeight;
    bi.biPlanes = ;
    bi.biBitCount      = bitmap->bmBitsPixel*;
    bi.biCompression   = BI_RGB;
    bi.biSizeImage     = ;
    bi.biXPelsPerMeter = ;
    bi.biYPelsPerMeter = ;
    bi.biClrUsed       = ;
    bi.biClrImportant  = ;
    fh = CreateFile(lpFileName, GENERIC_WRITE, , NULL, CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
    if (fh == INVALID_HANDLE_VALUE) return FALSE;
    bmfHdr.bfType = 0x4D42; // "BM"
    bmfHdr.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER)+bitmap->bmWidth*bitmap->bmHeight*bitmap->bmBitsPixel;
    bmfHdr.bfReserved1 = ;
    bmfHdr.bfReserved2 = ;
    bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER);
    WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
    WriteFile(fh, (char *)&bi,sizeof(BITMAPINFOHEADER), &dwWritten, NULL);
    WriteFile(fh, (char *)lpBuf,bitmap->bmWidth*bitmap->bmHeight*bitmap->bmBitsPixel, &dwWritten, NULL);
    FlushFileBuffers(fh);
    CloseHandle(fh);
    return true;
 }

 //(1)获取屏幕绘图设备
 //(2)创建一个与屏幕绘图设备相兼容的内存绘图设备
 //(2)在内存中创建一个与屏幕绘图设备相兼容的图像对象
 //(3)将屏幕设备中的图像复制到内存绘图设备中
 //(4)将内存图像保存到文件中
 //相关函数：
 //GetDIBits:按位的方式返回指定的BITMAP，并按指定的格式存储到内存中
 int GetBitmapFromScreen(char *lpFileName) {
     char *lpBuf;
     HBITMAP hBitmap,hOld ;
     HDC hDC,hcDC;
     BITMAP bb;
     BITMAPINFO b;
     HANDLE hp,fh=NULL;
     DWORD dwX,dwY;

     dwX=GetSystemMetrics(SM_CXSCREEN);
     dwY=GetSystemMetrics(SM_CYSCREEN);
     hDC=GetDC(NULL);
     hcDC=CreateCompatibleDC(hDC);
     hBitmap=CreateCompatibleBitmap(hDC,dwX,dwY);
     hOld=(HBITMAP)SelectObject(hcDC,hBitmap);
     BitBlt(hcDC,, ,dwX,dwY, hDC, , , SRCCOPY);
     bb.bmWidth=dwX;
     bb.bmHeight =dwY;
     bb.bmPlanes = ;
     bb.bmWidthBytes=bb.bmWidth*;
     bb.bmBitsPixel=;
     bb.bmType=;
     b.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
     b.bmiHeader.biWidth        =dwX;
     b.bmiHeader.biHeight       =dwY;
     b.bmiHeader.biPlanes       =;
     b.bmiHeader.biBitCount     =*;
     b.bmiHeader.biCompression  =BI_RGB;
     b.bmiHeader.biSizeImage    =;
     b.bmiHeader.biXPelsPerMeter=;
     b.bmiHeader.biYPelsPerMeter=;
     b.bmiHeader.biClrUsed      =;
     b.bmiHeader.biClrImportant =;
     b.bmiColors[].rgbBlue     =;
     b.bmiColors[].rgbGreen    =;
     b.bmiColors[].rgbRed      =;
     b.bmiColors[].rgbReserved =;
     hp=GetProcessHeap();
     lpBuf=(char *)HeapAlloc(hp,HEAP_ZERO_MEMORY,bb.bmHeight*bb.bmWidth*);
     GetDIBits(hcDC,hBitmap,,dwY,lpBuf,&b,DIB_RGB_COLORS);
     SaveBitmapToFile(&bb,lpFileName,lpBuf);
     ReleaseDC(NULL,hDC);
     DeleteDC(hcDC);
     DeleteObject(hBitmap);
     DeleteObject(hOld);
     HeapFree(hp,,lpBuf);
     return true;
 }