C# 通过拖动绘制线条

如何像windows画图那样画一条线，单击固定第一个点，第二个点（和线）随鼠标移动，再单击固定线。

int x = 0, y = 0;
protected override void OnMouseMove(MouseEventArgs e)
{
    base.OnMouseMove(e);
    // Create the graphics object
    Graphics g = CreateGraphics();
    // Create the pen that will draw the line
    Pen p = new Pen(Color.Navy);
    // Create the pen that will erase the line
    Pen erase = new Pen(Color.White);
    g.DrawLine(erase, 0, 0, x, y);
    // Save the mouse coordinates
    x = e.X; y = e.Y;
    g.DrawLine(p, 0, 0, x, y);
}

点击事件部分很好，但是使用上面的方法，擦除线实际上是白线，它重叠在其他背景图像和之前绘制的蓝线上。

有没有更易于管理的方法来实现这一目标？谢谢

窗体客户区上的任何绘图都应在OnPaint事件以避免任何奇怪的影响。 考虑以下代码片段：

Point Latest { get; set; }

List<Point> _points = new List<Point>(); 

protected override void OnMouseMove(MouseEventArgs e)
{
    base.OnMouseMove(e);

    // Save the mouse coordinates
    Latest = new Point(e.X, e.Y);

    // Force to invalidate the form client area and immediately redraw itself. 
    Refresh();
}

protected override void OnPaint(PaintEventArgs e)
{
    var g = e.Graphics;
    base.OnPaint(e);

    if (_points.Count > 0)
    {
        var pen = new Pen(Color.Navy);
        var pt = _points[0];
        for(var i=1; _points.Count > i; i++)
        {
            var next = _points[i];
            g.DrawLine(pen, pt, next);
            pt = next;
        }

        g.DrawLine(pen, pt, Latest);
    }
}

private void Form1_MouseClick(object sender, MouseEventArgs e)
{
    Latest = new Point(e.X, e.Y);
    _points.Add(Latest);
    Refresh();
}