c++ bitmap 截屏 MFC

****首先感謝巨人的肩膀，讓小白能夠走出bitmap圖片的苦海。****

   自己閑的沒事想通過c++ 的MFC來截屏并上傳服務器展示客戶端的當前界面。中間一路降妖伏魔....（此處省略2048個字節），發揚程序猿無私奉獻的優良品質，分享源代碼來眾生同樂。

1.好戲在前頭，請在.h添加下面這些東東....

typedef struct _BMPINFO

{

int  bmpWidth;//圖像的寬

int  bmpHeight;//圖像的高

int  biBitCount;//圖像類型，每像素位數

RGBQUAD  pColorTable[256];//顏色表指針

unsigned char pBmpBuf[10240000];

}m_bmpinfo,*p_bmpinfo;

//獲取截屏

void getScreen(char* filename);

int readBmp(const char* bmpName, unsigned char* pBmpBuf,int& bmpWidth,int& bmpHeight,int& biBitCount,RGBQUAD *pColorTable);

int sendReadBmp(char* filename,p_bmpinfo bmpinfo);

int recvSaveBmp(char* filename,p_bmpinfo bmpinfo);

int saveBmp(const char* bmpName,unsigned char *pBmpBuf,int& bmpWidth,int& bmpHeight,int& biBitCount,RGBQUAD *pColorTable);

--------------------------累了吧，關了網頁休息會--------------------------------------

2.截屏接口，保存截屏（格式為.bmp）到指定路徑

in char* filenam：需要保存截屏的文件路徑

void getScreen(char* filename)

{

    CDC *pDC;//屏幕DC

    pDC = CDC::FromHandle(GetDC(NULL));//獲取當前整個屏幕DC

    int BitPerPixel = pDC->GetDeviceCaps(BITSPIXEL);//獲得顏色模式

    int Width = pDC->GetDeviceCaps(HORZRES);

    int Height = pDC->GetDeviceCaps(VERTRES);

    CDC memDC;//內存DC

    memDC.CreateCompatibleDC(pDC);

    CBitmap memBitmap, *oldmemBitmap;//建立和屏幕兼容的bitmap

    memBitmap.CreateCompatibleBitmap(pDC, Width, Height);

    oldmemBitmap = memDC.SelectObject(&memBitmap);//將memBitmap選入內存DC

    memDC.BitBlt(0, 0, Width, Height, pDC, 0, 0, SRCCOPY);//復制屏幕圖像到內存DC

//以下代碼保存memDC中的位圖到文件

    BITMAP bmp;

    memBitmap.GetBitmap(&bmp);//獲得位圖信息

    FILE *fp = fopen(filename, "w+b");

    BITMAPINFOHEADER bih = {0};//位圖信息頭

    bih.biBitCount = bmp.bmBitsPixel;//每個像素字節大小

    bih.biCompression = BI_RGB;

    bih.biHeight = bmp.bmHeight;//高度

    bih.biPlanes = 1;

    bih.biSize = sizeof(BITMAPINFOHEADER);

    bih.biSizeImage = bmp.bmWidthBytes * bmp.bmHeight;//圖像數據大小

    bih.biWidth = bmp.bmWidth;//寬度

    BITMAPFILEHEADER bfh = {0};//位圖文件頭

    bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);//到位圖數據的偏移量

    bfh.bfSize = bfh.bfOffBits + bmp.bmWidthBytes * bmp.bmHeight;//文件總的大小

    bfh.bfType = (WORD)0x4d42;

    fwrite(&bfh, 1, sizeof(BITMAPFILEHEADER), fp);//寫入位圖文件頭 

    fwrite(&bih, 1, sizeof(BITMAPINFOHEADER), fp);//寫入位圖信息頭

    byte * p = new byte[bmp.bmWidthBytes * bmp.bmHeight];//申請內存保存位圖數據

    GetDIBits(memDC.m_hDC, (HBITMAP) memBitmap.m_hObject, 0, Height, p, 

        (LPBITMAPINFO) &bih, DIB_RGB_COLORS);//獲取位圖數據

    fwrite(p, 1, bmp.bmWidthBytes * bmp.bmHeight, fp);//寫入位圖數據

    delete [] p;   

    fclose(fp);

    memDC.SelectObject(oldmemBitmap);

}

--------------------------累了吧，后面沒有了--------------------------------------

-----------------------------------------------------------------------------------

3.讀取指定位置BMP相關信息到內存中

in const char* bmpName, BMP路徑

out unsigned char* pBmpBuf,BMP數據信息

out int& bmpWidth,BMP寬度

out int& bmpHeight,BMP高度

out int& biBitCount,BMP的像素位數

out RGBQUAD *pColorTable色彩版

int readBmp(const char* bmpName, unsigned char* pBmpBuf,int& bmpWidth,int& bmpHeight,int& biBitCount,RGBQUAD *pColorTable)

{

FILE *fp=fopen(bmpName,"rb");

if(fp==0)

{

printf("cannot open file");

return FALSE;

}

fseek(fp,sizeof(BITMAPFILEHEADER),0);

BITMAPINFOHEADER head;

fread(&head,sizeof(BITMAPINFOHEADER),1,fp);

bmpWidth = head.biWidth;

bmpHeight = head.biHeight;

biBitCount = head.biBitCount;

int lineByte = (bmpWidth *biBitCount/8+3)/4*4;//計算圖像每行像素所占的字節數

if(biBitCount == 8)

{

pColorTable = new RGBQUAD[256];

fread(pColorTable,sizeof(RGBQUAD),256,fp);

}

fread(pBmpBuf,1,lineByte *bmpHeight,fp);

fclose(fp);

return TRUE;

}

3.1 便于上層調用和重構提供一個封裝接口，將所有參數到一個結構體中，可便于socket傳輸（我4不4很聰明，請叫我少先隊員）

in char* filename,BMP路徑

out p_bmpinfo bmpinfo BMP數據結構體

int sendReadBmp(char* filename,p_bmpinfo bmpinfo)

{

if(readBmp(filename, bmpinfo->pBmpBuf, bmpinfo->bmpWidth, bmpinfo->bmpHeight, bmpinfo->biBitCount, bmpinfo->pColorTable))

{

return TRUE;

}

return FALSE;

}

--------------------累了吧，么有了------------------------------------------------------

--------------------累了吧，真的么有了----------------------------------------------------

--------------------真的，真的么有了----------------------------------------------------

4.將內存中的BMP數據寫入到本地文件

in const char* bmpName, 本地需保存的BMP文件路徑

in unsigned char *pBmpBuf,read得到的BMP數據

in int& bmpWidth,BMP寬度

in int& bmpHeight,BMP高度

in int& biBitCount,BMP像素位數

in RGBQUAD *pColorTable調色板

int saveBmp(const char* bmpName,unsigned char *pBmpBuf,int& bmpWidth,int& bmpHeight,int& biBitCount,RGBQUAD *pColorTable)

{

if(!pBmpBuf)//imgBuf 待存盤的位圖數據

return 0;

int i,j;

//每行字節數

int lineByte=(bmpWidth*biBitCount/8+3)/4*4;

//循環變量，針對彩×××像，遍歷每像素的三個分量

int k;

//將圖像左下角1/4部分置成黑色

if(biBitCount==8)

{//對于灰度圖像

for(i=0;i<bmpHeight/2;i++)

{

for(j=0;j<bmpWidth/2;j++)

{

*(pBmpBuf+i*lineByte+j)=0;

}

}

}

else if(biBitCount==24)

{//彩×××像

for(i=0;i<bmpHeight/2;i++)

{

for(j=0;j<bmpWidth/2;j++)

{

for(k=0;k<3;k++)//每像素RGB三個分量分別置0才變成黑色

*(pBmpBuf+i*lineByte+j*3+k)=0;

}

}

}

int colorTablesize = 0;

if(biBitCount == 8)

colorTablesize = 1024;

FILE *fp = fopen(bmpName,"wb");

if(fp == 0) return 0;

BITMAPFILEHEADER fileHead;

fileHead.bfType= 0x4d42;

fileHead.bfSize = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER) + colorTablesize + lineByte *bmpHeight;

fileHead.bfReserved1 = 0;

fileHead.bfReserved2 = 0;

fileHead.bfOffBits = 54 +colorTablesize;

fwrite(&fileHead,sizeof(BITMAPFILEHEADER),1,fp);

BITMAPINFOHEADER head;

head.biBitCount = biBitCount;

head.biClrImportant = 0;

head.biClrUsed = 0;

head.biCompression = 0;

head.biHeight = bmpHeight;

head.biPlanes =1;

head.biSize = 40;

head.biSizeImage = lineByte *bmpHeight;

head.biWidth = bmpWidth;

head.biXPelsPerMeter = 0;

head.biYPelsPerMeter = 0;

fwrite(&head,sizeof(BITMAPINFOHEADER),1,fp);

if(biBitCount == 8)

fwrite(pColorTable,sizeof(RGBQUAD),256,fp);

fwrite(pBmpBuf,bmpHeight * lineByte,1,fp);

fclose(fp);

return TRUE;

}

4.1 便于socket將接收到的結構體寫入本地文件，上層封裝了一層，主要與3.1配套使用

int recvSaveBmp(char* filename,p_bmpinfo bmpinfo)

{

saveBmp(filename, bmpinfo->pBmpBuf, bmpinfo->bmpWidth, bmpinfo->bmpHeight, bmpinfo->biBitCount, bmpinfo->pColorTable);

return TRUE;

}

---------------------------------測試代碼------------------------------------------------
發送端：

p_bmpinfo bmpinfo = (p_bmpinfo)malloc(sizeof(m_bmpinfo));

sendReadBmp(sFileName,bmpinfo);

socketSend(client,(char*)bmpinfo,sizeof(m_bmpinfo));//socket發送

接收端：

p_bmpinfo bmpinfo = (p_bmpinfo)malloc(sizeof(m_bmpinfo));

int len;

SOCKET socket = socketAccept(server); //socket監聽

do {

len = socketRecv(socket,(char*)bmpinfo,sizeof(m_bmpinfo));//socket接受數據

recvSaveBmp(sFileName,bmpinfo);

} while(0 != len);

--------------------------------么有了，木騙你------------------------------------

--------------------------------么有了，俺真木騙你------------------------------------