问题是这样的,我画曲线后,当曲线画到某一点时候,判断这个点是不是需要加强显示,如果是,就以该点为中心画一个实心圆,但是这么一来,就把前面画的曲线给覆盖了,所以我就想能不能画一个透明的实心圆,这样就不覆盖前面的曲线? 我这里不能先画圆圈再画曲线,所以不能从画图顺序角度解决这个问题,请高手指点! 目前代码如下:
CBrush * pOldBrush = pDC- >SelectObject( &brushS );//画实心圆
pDC- >Ellipse(prePoint.x-9/x_times,prePoint.y-9/x_times,prePoint.x+9/x_times,prePoint.y+9/x_times);
pDC- >SelectObject( pOldBrush );
CBrush * pOldBrush = pDC- >SelectObject( &brushS );//画实心圆
pDC- >Ellipse(prePoint.x-9/x_times,prePoint.y-9/x_times,prePoint.x+9/x_times,prePoint.y+9/x_times);
pDC- >SelectObject( pOldBrush );
CBrush *bs = CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));//选择透明画刷
CBrush *oldBs = dc.SelectObject(bs);