这段代码运行为何重复运行四五十次就不行了?

Question

BOOL Capture(HWND hWnd,RECT pircRect,CString picstrFilename,int piiSerial)
{
HBITMAP hDesktopCompatibleBitmap=NULL;
HDC hDesktopCompatibleDC=NULL;
HDC hDesktopDC=NULL;
HWND hDesktopWnd=NULL;

hDesktopWnd=GetDesktopWindow();
hDesktopDC=GetDC(hDesktopWnd);
hDesktopCompatibleDC=CreateCompatibleDC(hDesktopDC);
hDesktopCompatibleBitmap=CreateCompatibleBitmap(hDesktopDC,GetSystemMetrics(SM_CXSCREEN),GetSystemMetrics(SM_CYSCREEN));
SelectObject(hDesktopCompatibleDC,hDesktopCompatibleBitmap); BitBlt(hDesktopCompatibleDC,0,0,GetSystemMetrics(SM_CXSCREEN),GetSystemMetrics(SM_CYSCREEN),hDesktopDC,0,0,SRCCOPY); BITMAPINFO bi;
void *         pBits=NULL;
int  nWidth=GetSystemMetrics(SM_CXSCREEN);
int  nHeight=GetSystemMetrics(SM_CYSCREEN);
ZeroMemory(&bi,sizeof(bi));
bi.bmiHeader.biSize=sizeof(bi.bmiHeader);
bi.bmiHeader.biHeight=nHeight;
bi.bmiHeader.biWidth=nWidth;
bi.bmiHeader.biPlanes=1;
bi.bmiHeader.biBitCount=24;
bi.bmiHeader.biCompression=BI_RGB;
bi.bmiHeader.biSizeImage=3*nWidth * nHeight;
HDC hBmpFileDC=CreateCompatibleDC(hDesktopCompatibleDC);
HBITMAP hBmpFileBitmap=CreateDIBSection(hDesktopCompatibleDC,&bi,DIB_RGB_COLORS,&pBits,NULL,0);
SelectObject(hBmpFileDC,hBmpFileBitmap);
BitBlt(hBmpFileDC,0,0,nWidth,nHeight,hDesktopCompatibleDC,0,0,SRCCOPY);// if(piiSerial > 140)
{
HANDLE hFile = CreateFile(picstrFilename,GENERIC_WRITE,FILE_SHARE_WRITE,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
if(hFile!=INVALID_HANDLE_VALUE)
{
DWORD dwRet=0;
BITMAPFILEHEADER bmfHeader;
ZeroMemory(&bmfHeader,sizeof(bmfHeader));
bmfHeader.bfOffBits=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
bmfHeader.bfSize=bi.bmiHeader.biSizeImage+bmfHeader.bfOffBits;
bmfHeader.bfType='MB';

WriteFile(hFile,&bmfHeader,sizeof(bmfHeader),&dwRet,NULL);
WriteFile(hFile,&bi.bmiHeader,sizeof(bi.bmiHeader),&dwRet,NULL);
WriteFile(hFile,pBits,bi.bmiHeader.biSizeImage,&dwRet,NULL);
CloseHandle(hFile);
}
}
DeleteDC(hBmpFileDC);
DeleteObject(hBmpFileBitmap); return TRUE;
}是抓屏的.
这个函数在一个循环里调用两百次.抓出来的前三四十个图是正确的.
后面的BMP文件即是黑屏了.但是能正常打开,和正常的图片大小一样.请问错在哪儿?谢谢!

Answer 1

DeleteObject(hDesktopCompatibleBitmap);

Answer 2

bi.bmiHeader.biSizeImage=3*nWidth * nHeight好象不对吧？
DWORD  dwBytesPerLine  =  (((lpbi->biWidth*lpbi->biBitCount+7)/8)+3)/4*4;  
bi.bmiHeader.biSizeImage =    dwBytesPerLine*lpbi->biHeight

Answer 3

内存泄露，hDesktopCompatibleBitmap

Answer 4

参考：
void CCaptureDlg::SaveBmp()
{
CDC dc;
dc.CreateDC("DISPLAY",NULL,NULL,NULL);
CBitmap bm;
int Width=GetSystemMetrics(SM_CXSCREEN);
int Height=GetSystemMetrics(SM_CYSCREEN);
bm.CreateCompatibleBitmap(&dc,Width,Height);
CDC tdc;
tdc.CreateCompatibleDC(&dc);
CBitmap*pOld=tdc.SelectObject(&bm);
tdc.BitBlt(0,0,Width,Height,&dc,0,0,SRCCOPY);
tdc.SelectObject(pOld);
BITMAP btm;
bm.GetBitmap(&btm);
DWORD size=btm.bmWidthBytes*btm.bmHeight;
LPSTR lpData=(LPSTR)GlobalAllocPtr(GPTR,size);
/////////////////////////////////////////////
BITMAPINFOHEADER bih;
bih.biBitCount=btm.bmBitsPixel;
bih.biClrImportant=0;
bih.biClrUsed=0;
bih.biCompression=0;
bih.biHeight=btm.bmHeight;
bih.biPlanes=1;
bih.biSize=sizeof(BITMAPINFOHEADER);
bih.biSizeImage=size;
bih.biWidth=btm.bmWidth;
bih.biXPelsPerMeter=0;
bih.biYPelsPerMeter=0;
///////////////////////////////////
GetDIBits(dc,bm,0,bih.biHeight,lpData,(BITMAPINFO*)&bih,DIB_RGB_COLORS);
// bm.GetBitmapBits(size,lpData); //此函数在处理5-5-5模式的16位色下会出现颜色混乱
//////////////////////////////
static int filecount=0;
CString name;
name.Format("pict%04d.bmp",filecount++);
name=m_Path+name;
BITMAPFILEHEADER bfh;
bfh.bfReserved1=bfh.bfReserved2=0;
bfh.bfType=((WORD)('M'<< 8)|'B');
bfh.bfSize=54+size;
bfh.bfOffBits=54;
CFile bf;
if(bf.Open(name,CFile::modeCreate|CFile::modeWrite)){
bf.WriteHuge(&bfh,sizeof(BITMAPFILEHEADER));
bf.WriteHuge(&bih,sizeof(BITMAPINFOHEADER));
bf.WriteHuge(lpData,size);
bf.Close();
nCount++;
}
GlobalFreePtr(lpData);
if(nCount==1)
m_Number.Format("%d picture captured.",nCount);
else
m_Number.Format("%d pictures captured.",nCount);
UpdateData(FALSE);
}

Answer 5

ReleaseDC(hDesktopWnd,hDesktopDC);
但你在循环中抓屏？？即便没有内存泄漏或是GDI泄漏的问题，你的显卡处理及总线处理得过来不？