从位图数据取得位图句柄

#include <windows.h>
#include <fstream>
using namespace std;

void main()
{
ifstream infile("bm.bmp", ios::in | ios::binary);

BITMAPFILEHEADER bmpHeader;
// 获取文件大小
infile.seekg(0, ios::end);
long nfilelen = infile.tellg();
infile.seekg(0, ios::beg);

// 读取文件头
infile.read((char*)&bmpHeader, sizeof(bmpHeader));
if (bmpHeader.bfType != 0x4d42)
return ;

// 占用一块内存
HGLOBAL hDIB = GlobalAlloc(GMEM_FIXED, nfilelen);
if (hDIB == 0)
return ;

// 把文件写入DIB
infile.read((char*)hDIB, nfilelen - sizeof(BITMAPFILEHEADER));

// 锁定内存, 位图信息指向该内存
// BITMAPINFO == 位图信息头 + 调色板
BITMAPINFO &bmpInfo = *(BITMAPINFO*)GlobalLock(hDIB);
// 位图信息头指向该内存
// BITMAPINFOHEADER *pInfoHead = (BITMAPINFOHEADER*)hDIB;

// 位图信息头大小
// int nHeadSize = sizeof(BITMAPINFOHEADER);
// 获取颜色数组
BYTE *pBmpPixelBuffer=(BYTE *)&bmpInfo + bmpHeader.bfOffBits - sizeof(BITMAPFILEHEADER);

HDC hDC = GetDC(NULL);
HBITMAP hBitmap;
hBitmap=CreateDIBitmap(hDC,(BITMAPINFOHEADER *)&bmpInfo,
CBM_INIT,(VOID *)pBmpPixelBuffer,&bmpInfo,DIB_RGB_COLORS);

HDC memDC;
memDC = CreateCompatibleDC(hDC);
SelectObject(memDC, hBitmap);
BitBlt(hDC, 0, 0, 500, 500, memDC, 0, 0, SRCCOPY);


DeleteDC(memDC);
GlobalFree(hDIB);
infile.close();
}