绘制直线的重绘问题

Question

   我在做一个简单的画板，做到了绘制知道的地方，但是再画第二次直线的时候就会把前面的一条直线给擦掉，请问谁有关于直线重绘的代码，帮忙给我介绍一下呀，急需！

Answer 1

private void pictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if (drawing)
            {
                    Graphics g = this.pictureBox1.CreateGraphics();
                    Pen backPen = new Pen(this.pictureBox1.BackColor);
                    g.DrawLine(backPen, this.start, this.end);
                    this.end.X = e.X;
                    this.end.Y = e.Y;
                    Pen forePen = new Pen(Color.Blue);
                    g.DrawLine(forePen, this.start, this.end);
                }
            }
private void pictureBox1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if (drawing)
            {
Graphics g = this.pictureBox1.CreateGraphics();
                    Pen backPen = new Pen(this.pictureBox1.BackColor);
                    g.DrawLine(backPen, this.start, this.end);
                    this.end.X = e.X;
                    this.end.Y = e.Y;
                    Pen forePen = new Pen(Color.Blue);
                    g.DrawLine(forePen, this.start, this.end);
                    this.drawing = false;                    this.drawing = false;
                array.Add(new Rectangle(this.start, new Size(this.width, this.height)));
}
            }这是我做的关于mousemove和mouseup的代码

Answer 2

每次都CreateGraphics，当然会被清除掉吧。
改用
Graphics g = Graphics.FromImage(pictureBox1.Image);
这样试试。还有画完了别忘了g.Dispose();

Answer 3

我还是新手，这个方法不懂，可不可以在我创建的代码的基础上写一下关于paint的重绘的代码呀？