but when call at some dlg,only no echo,but after add a Invalidate() ,it will be ok very strange.

void CAboutDlg::OnTestDraw()
{ Invalidate();
CPaintDC dc(this);
CPen MyNewPen;
COLORREF mm_color=RGB(233,44,55);//dlg.m_color;
MyNewPen.CreatePen(PS_SOLID,10,mm_color);//RGB(255,0,0)
CPen* pOriginalPen;
pOriginalPen=dc.SelectObject(&MyNewPen);
int m_Radius=22;
CRect MyRectangle(30,10,20+m_Radius*2,10+m_Radius*2);
dc.Ellipse(&MyRectangle);
dc.LineTo(235,444);
dc.SelectObject(pOriginalPen);
//CDialog::OnPaint();

}