如何檫掉繪制的直線？  
hdc  =  GetDC(glhTargetWnd);  
SelectObject(hdc,  pen);  
...  
LineTo(hdc,  100,  100);  
 
我想把這這條線擦下去，該怎么做  
 
---------------------------------------------------------------  
 
有異或方式再畫一遍。  
::SetROP2(hdc,R2_XORPEN);  
SelectObject(hdc,pen);  
...  
LineTo(hdc,100,100);  
---------------------------------------------------------------  
 
           CDC*  pDC  =  GetDC();  
           CPen  pen(PS_SOLID,4,RGB(128,0,0));  
             
           CPen*  pOldPen  =  pDC->SelectObject(&pen);  
           pDC->SetROP2(R2_XORPEN);  
           pDC->MoveTo(0,0);  
           pDC->LineTo(100,  100);  
           pDC->SelectObject(&pOldPen);  
           ReleaseDC(pDC);  
畫線的時候也用上SetROP2(R2_XORPEN);  
就是調用相同的代碼執行擦除和重畫動作就可以了