调用:
Graphics g = this.CreateGraphics();
Draw(g);
----------------
private void Draw(Graphics g)
{g.DrawLine(new Pen(Color.Black), new Point(20,20), new Point(200,40));
}
Graphics g = this.CreateGraphics();
Draw(g);
----------------
private void Draw(Graphics g)
{g.DrawLine(new Pen(Color.Black), new Point(20,20), new Point(200,40));
}
我在单击按钮事件中调用了Draw()方法,每点一次按钮都重新画一次图形,
但是上一次画的图形没有清除,怎么清除上一次画的图呢?