怎样用对话框打开24位的位图文件并显示

Question

位图文件一般用LoadImage来装入，而CFileDialog一般只是给出你选的文件名

Answer 1

void CDemoDlg::OnBtnOpen() 
{  
    CDC *pDC=GetDC(); BITMAPFILEHEADER bmfh;
BITMAPINFOHEADER bmih; CFileDialog dlg(TRUE,"*.bmp","001.bmp",OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
     "BMP Files(dlg*.bmp)|*.bmp||");

CString msg;
int iResult;
iResult=dlg.DoModal();
if(iResult==IDOK)
{
CString msg;
msg+=dlg.GetFileName();
}

CFile *fp;
fp=new CFile();
fp->Open(msg,CFile::modeRead);
fp->SeekToBegin();
fp->Read(&bmfh,sizeof(bmfh));
fp->Read(&bmih,sizeof(bmih)); RGBTRIPLE * rgb=new RGBTRIPLE[bmih.biWidth*bmih.biHeight];
fp->SeekToBegin();
fp->Seek(54,CFile::begin);
fp->Read(rgb,bmih.biWidth*bmih.biHeight*3);
    

}
fp->Close();
delete fp;
delete rgb;
}

Answer 2

void CDemoDlg::OnPaint() 
{
if (IsIconic())
{
CPaintDC dc(this); // device context for painting SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0); // Center icon in client rectangle
int cxIcon = GetSystemMetrics(SM_CXICON);
int cyIcon = GetSystemMetrics(SM_CYICON);
CRect rect;
GetClientRect(&rect);
int x = (rect.Width() - cxIcon + 1) / 2;
int y = (rect.Height() - cyIcon + 1) / 2; // Draw the icon
dc.DrawIcon(x, y, m_hIcon);
}
else
{
CDialog::OnPaint();
}
if(!bitmap.m_hObject)
return;
CRect rct;
m_image.GetClientRect(&rct);
HDC hDC = pDC->GetSafeHdc();

SetStretchBltMode(hDC,HALFTONE); BITMAPINFO  bitmapInfo;
bitmapInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bitmapInfo.bmiHeader.biWidth = bmp.bmWidth;
bitmapInfo.bmiHeader.biHeight = bmp.bmHeight;
bitmapInfo.bmiHeader.biPlanes = 1;
bitmapInfo.bmiHeader.biBitCount = 24;
bitmapInfo.bmiHeader.biCompression = BI_RGB;
bitmapInfo.bmiHeader.biClrUsed =0; StretchDIBits(hDC,0,0,rct.Width(),rct.Height(),0,bmp.bmHeight,bmp.bmWidth,-bmp.bmHeight,rgb,&bitmapInfo,DIB_RGB_COLORS,SRCCOPY);
}