我开发了一个应用程序，它每隔1000/30毫秒拍摄一次DESKTOP快照。申请将持续10分钟。所以在10分钟内它应该可以节省18000个快照，但它只有大约80个快照。我不知道为什么会这样。
我的代码在这里： -
#include "windows.h" // should be less than and greater than instead of \"
#include "string.h"
int CaptureBMP(LPCTSTR szFile)
{
// Source[1]
HDC hdcScr, hdcMem;
HBITMAP hbmScr;
BITMAP bmp;
int iXRes, iYRes;
// Create a normal DC and a memory DC for the entire screen. The
// normal DC provides a "snapshot" of the screen contents. The
// memory DC keeps a copy of this "snapshot" in the associated
// bitmap.
hdcScr = CreateDC("DISPLAY", NULL, NULL, NULL);
hdcMem = CreateCompatibleDC(hdcScr);
iXRes = GetDeviceCaps(hdcScr, HORZRES);
iYRes = GetDeviceCaps(hdcScr, VERTRES);
// Create a compatible bitmap for hdcScreen.
hbmScr = CreateCompatibleBitmap(hdcScr, iXRes, iYRes);
if (hbmScr == 0) return 0;
// Select the bitmaps into the compatible DC.
if (!SelectObject(hdcMem, hbmScr)) return 0;
// Copy color data for the entire display into a
// bitmap that is selected into a compatible DC.
if (!StretchBlt(hdcMem,
0, 0, iXRes, iYRes,
hdcScr,
0, 0, iXRes, iYRes,
SRCCOPY))
return 0;
// Source[2]
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap's color format, width, and height.
if (!GetObject(hbmScr, sizeof(BITMAP), (LPSTR) &bmp)) return 0;
// Convert the color format to a count of bits.
cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits != 24)
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,
sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1 << cClrBits));
// There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,
sizeof(BITMAPINFOHEADER));
// Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
pbmi->bmiHeader.biClrUsed = (1 << cClrBits);
// If the bitmap is not compressed, set the BI_RGB flag.
pbmi->bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
pbmi->bmiHeader.biSizeImage = (pbmi->bmiHeader.biWidth + 7) / 8
* pbmi->bmiHeader.biHeight * cClrBits;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header
PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbmi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits) return 0;
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hdcMem, hbmScr, 0, (WORD) pbih->biHeight, lpBits, pbmi, DIB_RGB_COLORS)) return 0;
// Create the .BMP file.
hf = CreateFile(szFile,
GENERIC_READ | GENERIC_WRITE,
(DWORD) 0,
NULL,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL,
(HANDLE) NULL);
if (hf == INVALID_HANDLE_VALUE) return 0;
hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed *
sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL)) return 0;
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER)
+ pbih->biClrUsed * sizeof (RGBQUAD),
(LPDWORD) &dwTmp, NULL))
return 0;
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp, NULL)) return 0;
// Close the .BMP file.
if (!CloseHandle(hf)) return 0;
// Free memory.
GlobalFree((HGLOBAL)lpBits);
ReleaseDC(0, hdcScr);
ReleaseDC(0, hdcMem);
return 1;
}
void main()
{
int index =0;
char str[50];
char pmp[10]=".bmp";
LPCTSTR szFile;
Sleep(5000);
DWORD tickes=0;
DWORD timespan = 1000/30;
DWORD diff ;
DWORD entry=GetTickCount() +30000;
while(entry>tickes)
{
char num[500]="C:\\SANSHOT\\";
diff=GetTickCount() - tickes;
tickes=GetTickCount();
if(diff<timespan)
{
Sleep(timespan-diff);
}
itoa(index, str, 10);
strcat(num,str);
strcat(num,pmp);
szFile = num;
CaptureBMP(szFile);
index++;
}
}
我不知道问题是什么，在哪里。
有人可以帮我解决这个问题。
...谢谢
答案 0 :(得分：0)
我认为你的问题是暂时的。您的程序运行10分钟，但大约30秒（DWORD entry=GetTickCount() + 30000）。然后满足条件entry > tickes并且循环中止。在这短短的时间内，您的应用程序只能设置80 bmp。如果您希望它运行10分钟，则该数字不能是30000，而是600000（10分钟* 60 * 1000 = 600000毫秒）