onpaint之后为什么没有反应?
void CDlgISOShow::OnPaint()
{
CPaintDC dc(this); // device context for painting
CRect rect;
GetDlgItem(IDC_ISO)->GetWindowRect(rect);
ScreenToClient(rect);
int Length,Width,step;
Length = rect.right-rect.left;
Width = rect.bottom-rect.top;
dc.MoveTo(rect.left,rect.top+Width/2);
dc.LineTo(rect.right,rect.top+Width/2);
}
哪里有错?