怎样生成一位图，128*128，底色黑，正中为字“hello”，字体在程序中修改。

Question

怎样在程序中生成这样一位图呢？比如保存为1.bmp

Answer 1

DEMO
在对话框上放一个Static,ID:IDC_STATIC_BMP用于显示BMP
一个Button用于生成BMP.void CTestDlg::OnButton1() 
{
HWND hDispHwnd = GetDlgItem(IDC_STATIC_BMP)->GetSafeHwnd();
HDC dc = ::GetDC(hDispHwnd);
HDC dcMem;
dcMem = ::CreateCompatibleDC(dc); HBITMAP hBitmap = ::CreateCompatibleBitmap(dc , 128 ,128);
HBITMAP hOldBm = (HBITMAP)::SelectObject(dcMem , hBitmap);
SetBkColor(dcMem , RGB(255,255,255));
SetTextColor(dcMem , RGB(0,0,0)); LOGFONT logFont;
memset(&logFont, 0, sizeof(LOGFONT));
logFont.lfHeight = 20; 
lstrcpy(logFont.lfFaceName, _T("Arial")); HFONT hFont = CreateFontIndirect(&logFont); HFONT oldFont = (HFONT)SelectObject( dcMem , hFont); SetBkColor(dcMem , RGB(255,255,255));

SetTextColor(dcMem , RGB(0,0,0,));
SIZE size;
GetTextExtentPoint32(dcMem , "Hello" , 5 , &size); TextOut(dcMem , (128 - size.cx) /2 , (128 - size.cy) /2 , "Hello" , 5);

BitBlt( dc , 0 , 0 , 128 , 128 , dcMem , 0 , 0 ,  SRCCOPY);
SelectObject(dcMem , hOldBm);
SelectObject(dcMem , oldFont);
::DeleteDC(dcMem);
SaveBmp(hBitmap , "E:\\Temp.bmp");
DeleteObject(hBitmap);
DeleteObject(hFont);
::ReleaseDC( m_hWnd , dc);

}BOOL CTestDlg::SaveBmp(HBITMAP hBitmap, CString FileName)
{
HDC hDC;
int iBits;
WORD wBitCount;
DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0; 
BITMAP Bitmap;  
BITMAPFILEHEADER bmfHdr;  
BITMAPINFOHEADER bi;  
LPBITMAPINFOHEADER lpbi;  
HANDLE fh, hDib, hPal,hOldPal=NULL; 

hDC = CreateDC("DISPLAY", NULL, NULL, NULL);
iBits = GetDeviceCaps(hDC, BITSPIXEL) * GetDeviceCaps(hDC, PLANES); 
DeleteDC(hDC); 
if (iBits <= 1) wBitCount = 1; 
else if (iBits <= 4)  wBitCount = 4; 
else if (iBits <= 8)  wBitCount = 8; 
else   wBitCount = 24; 

GetObject(hBitmap, sizeof(Bitmap), (LPSTR)&Bitmap);
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = Bitmap.bmWidth;
bi.biHeight = Bitmap.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = wBitCount;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrImportant = 0;
bi.biClrUsed = 0;

dwBmBitsSize = ((Bitmap.bmWidth * wBitCount + 31) / 32) * 4 * Bitmap.bmHeight;

hDib = GlobalAlloc(GHND,dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER)); 
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib); 
*lpbi = bi; 

hPal = GetStockObject(DEFAULT_PALETTE); 
if (hPal) 
{ 
hDC = ::GetDC(NULL); 
hOldPal = ::SelectPalette(hDC, (HPALETTE)hPal, FALSE); 
RealizePalette(hDC); 
}

GetDIBits(hDC, hBitmap, 0, (UINT) Bitmap.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER) 
+dwPaletteSize, (BITMAPINFO *)lpbi, DIB_RGB_COLORS); 

if (hOldPal) 
{ 
::SelectPalette(hDC, (HPALETTE)hOldPal, TRUE); 
RealizePalette(hDC); 
::ReleaseDC(NULL, hDC); 
} 

fh = CreateFile(FileName, GENERIC_WRITE,0, NULL, CREATE_ALWAYS, 
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL); 

if (fh == INVALID_HANDLE_VALUE)  return FALSE; 

bmfHdr.bfType = 0x4D42; // "BM" 
dwDIBSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwPaletteSize + dwBmBitsSize;  
bmfHdr.bfSize = dwDIBSize; 
bmfHdr.bfReserved1 = 0; 
bmfHdr.bfReserved2 = 0; 
bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER) + dwPaletteSize;  WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL); 
WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);  GlobalUnlock(hDib); 
GlobalFree(hDib); 
CloseHandle(fh); 

return TRUE;

}

Answer 2

Sorry,
Release( m_hWnd , dc);
应为::ReleaseDC( hDispHwnd , dc);

Answer 3

lanstar200(码雅哥布林) ，这段代码非常适合，可是中间的字的显示区域的背景色不和位图的一样，我设为透明，就显示不出字了，怎么解决？

Answer 4

把
SetBkColor(dcMem , RGB(255,255,255));
SetTextColor(dcMem , RGB(0,0,0,));
改成
SetBkMode(dcMem , TRANSPARENT);
SetTextColor(dcMem , RGB(255,255,255));

Answer 5

RGB(0,0,0)是黑色，跟背景色相同了，设成其他颜色就OK了

Answer 6

怎么改了SetBkColor(dcMem , RGB(255,0,0));还是底色黑色？

Answer 7

//字体
logFont.lfHeight = 20; //字体高度
lstrcpy(logFont.lfFaceName, _T("Arial"));//字体名称
//字体颜色改变下面两个函数的RGB值
SetBkColor(dcMem , RGB(0,0,0));//背景色
SetTextColor(dcMem , RGB(255,255,255));//字体颜色

Answer 8

调用了SetBkColor就不能再用SetBkMode(dcMem , TRANSPARENT);了这句是使用透明背景色

Answer 9

void CTestDlg::OnButton1() 
{
HWND hDispHwnd = GetDlgItem(IDC_STATIC_BMP)->GetSafeHwnd();
HDC dc = ::GetDC(hDispHwnd);
HDC dcMem;
dcMem = ::CreateCompatibleDC(dc); HBITMAP hBitmap = ::CreateCompatibleBitmap(dc , 128 ,128);
HBITMAP hOldBm = (HBITMAP)::SelectObject(dcMem , hBitmap);

LOGBRUSH logbr;
memset(&logbr , 0 , sizeof(LOGBRUSH));
logbr.lbColor = RGB(255,0,0);//这里改变位图背景
logbr.lbStyle = BS_SOLID;
HBRUSH hBrush = CreateBrushIndirect(&logbr);
HBRUSH oldbr = (HBRUSH)SelectObject(dcMem , hBrush); RECT rt = {0,0,128,128};
FillRect(dcMem , &rt , hBrush);
LOGFONT logFont;
memset(&logFont, 0, sizeof(LOGFONT));
logFont.lfHeight = 20; 
lstrcpy(logFont.lfFaceName, _T("Arial")); HFONT hFont = CreateFontIndirect(&logFont); HFONT oldFont = (HFONT)SelectObject( dcMem , hFont); //SetBkColor( dcMem , RGB(255,0,0));
SetBkMode(dcMem , TRANSPARENT);
SetTextColor(dcMem , RGB(255,255,255)); SIZE size;
GetTextExtentPoint32(dcMem , "Hello" , 5 , &size); TextOut(dcMem , (128 - size.cx) /2 , (128 - size.cy) /2 , "Hello" , 5);

BitBlt( dc , 0 , 0 , 128 , 128 , dcMem , 0 , 0 ,  SRCCOPY);
SelectObject(dcMem , hOldBm);
SelectObject(dcMem , oldFont);
SelectObject(dcMem , oldbr);
::DeleteDC(dcMem);
SaveBmp(hBitmap , "E:\\Temp.bmp");
DeleteObject(hBitmap);
DeleteObject(hFont);
DeleteObject(hBrush);
::ReleaseDC( hDispHwnd , dc);

}