c#画线Graphics

简单的画线，郁闷了我好几天

 

在panel和pictureBox中的画法都是一样的

 

public void pictureBox1_ht()//画图的简单方法

{
      Graphics g = pictureBox1.CreateGraphics();
      g.DrawLine(new Pen(Color.Red, 2), x, 20, x, 40);
}

 

private void button2_Click(object sender, EventArgs e)
{
            x = Convert.ToInt32(textBox1.Text);
            y = Convert.ToInt32(textBox1.Text);

            pictureBox1.Invalidate();//刷新 pictureBox图  要是只有这句话 还要重写OnPaint方法

            //pictureBox1.Load("tt.bmp");//重新加载图片  图片位置在bin中

 

           pictureBox1.Update();//这句话相当关键  会是消除之前画的图 速度加快

            pictureBox1_ht();
}

 

//--------------------------------------------------

 

protected override void OnPaint(PaintEventArgs e)//重写 
{
         panel1_ht();
}

public void panel1_ht()
{
           Graphics g = pictureBox1.CreateGraphics();
           g.DrawLine(new Pen(Color.Red, 2), x, 20, x, 40);
}

 

private void button2_Click(object sender, EventArgs e)
{
           x = Convert.ToInt32(textBox1.Text);
           y = Convert.ToInt32(textBox1.Text);
           pictureBox1.Invalidate();
           //pictureBox1.Load("tt.bmp");
           //ctureBox1.Update();
           panel1_ht();
}