VC打开一个文件代码

void CMySerialPortDlg::OnOpenFile()
{
// TODO: Add your control notification handler code here
CString sFileFilter="*.hex|*.hex";
CString sFileName;
CFileDialog fDlg(true,NULL,NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,sFileFilter,NULL);
fDlg.DoModal();
sFileName=fDlg.GetFileName();
if(sFileName!="")
{
CFile file(sFileName,CFile::modeRead);
int nFileLength=file.GetLength();
char *buffer;
HGLOBAL hgl=::GlobalAlloc(GMEM_MOVEABLE,nFileLength+1);
buffer=(char *)::GlobalLock(hgl);
file.Read(buffer,nFileLength);
SetDlgItemText(IDC_SENDDATA,buffer);
::GlobalUnlock(hgl);
::GlobalFree(hgl);

}
UpdateData(false);

}