Question

为什么我的GetClientRect得到的全是0

Answer 1

CWnd::GetClientRect
void GetClientRect(
LPRECT lpRect )
const;
此函数用来获取对话框客户区大小。按你的代码，通过rc.Width()和rc.Height()就可以获得客户区的宽度和高度。

示例：绘制一条正弦曲线
void CMainWindow::OnPaint()
{
CPaintDC dc(this);
CRect rect;
GetClientRect(rect);
int nWidth = rect.Width();
int nHeight = rect.Height();
CPoint aPoint[SEGMENT];
for (int i=0; i<SEGMENT; i++)
{
aPoint[i].x = (i * nWidth) / SEGMENT;
aPoint[i].y = (int) ((nHeight / 2) * (1 - (sin((2*PI*i)/SEGMENT))));
}
dc.Polyline(aPoint,SEGMENT);
}