如何在内存的bitmap上写字？？

Question

知道buffer,和width height,如何在上面写透明的字？

Answer 1

CDC::SetBkMode(TRANSPARENT);
CDC::TextOut(...);

Answer 2

void AddNameTime(HBITMAP hBm,int iWidth, int iHeight, BOOL bAddName,BOOL bAddTime,CString sName,CTime t,DWORD dwColor,DWORD dwNameAlign,DWORD dwTimeAlign){
if (bAddTime || bAddName)
{
CString sTime;
sTime.Format("%04d-%02d-%02d %02d:%02d:%02d",t.GetYear(), t.GetMonth(), t.GetDay(),t.GetHour(), t.GetMinute(), t.GetSecond());

CDC dc;
dc.CreateCompatibleDC(NULL);
CBitmap * pSaveBmp = dc.SelectObject(CBitmap::FromHandle(hBm));
CFont font;
font.CreateFont(14,0,0,0,FW_THIN,0,0,0,DEFAULT_CHARSET,0,0,0,0,"Thamo");
CFont * pSaveFont = dc.SelectObject(&font);
dc.SetBkMode(TRANSPARENT);
dc.SetTextColor(dwColor);
INT iLeft =0;
INT iTop =0;
INT iRight = iWidth;
INT iBottom = abs(iHeight);
INT left=0,top=0;
switch(dwNameAlign)
{
case 0:
dc.SetTextAlign(TA_LEFT|TA_TOP);
left = iLeft+2;
top = iTop+2;
break;
case 1:
dc.SetTextAlign(TA_LEFT|TA_BOTTOM);
left = iLeft+2;
top = iBottom-2;
break;
case 2:
dc.SetTextAlign(TA_RIGHT|TA_TOP);
left = iRight-2;
top = iTop+2;
break;
case 3:
dc.SetTextAlign(TA_RIGHT|TA_BOTTOM);
left = iRight-2;
top = iBottom-2;
break;
case 4:
dc.SetTextAlign(TA_CENTER|TA_TOP);
left = (iLeft+iRight)/2;
top = iTop+2;
break;
case 5:
dc.SetTextAlign(TA_CENTER|TA_BOTTOM);
left = (iLeft+iRight)/2;
top = iBottom-2;
break;
}
dc.TextOut(left,top,sName);
switch(dwTimeAlign)
{
case 0:
dc.SetTextAlign(TA_LEFT|TA_TOP);
left = iLeft+2;
top = iTop+2;
break;
case 1:
dc.SetTextAlign(TA_LEFT|TA_BOTTOM);
left = iLeft+2;
top = iBottom-2;
break;
case 2:
dc.SetTextAlign(TA_RIGHT|TA_TOP);
left = iRight-2;
top = iTop+2;
break;
case 3:
dc.SetTextAlign(TA_RIGHT|TA_BOTTOM);
left = iRight-2;
top = iBottom-2;
break;
case 4:
dc.SetTextAlign(TA_CENTER|TA_TOP);
left = (iLeft+iRight)/2;
top = iTop+2;
break;
case 5:
dc.SetTextAlign(TA_CENTER|TA_BOTTOM);
left = (iLeft+iRight)/2;
top = iBottom-2;
break;
}
dc.TextOut(left,top,sTime);
dc.SelectObject(pSaveFont);
dc.SelectObject(pSaveBmp);
}
}