c#畫線Graphics

簡單的畫線，郁悶了我好幾天

 

在panel和pictureBox中的畫法都是一樣的

 

public void pictureBox1_ht()//畫圖的簡單方法

{
      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圖  要是只有這句話 還要重寫OnPaint方法

            //pictureBox1.Load("tt.bmp");//重新加載圖片  圖片位置在bin中

 

           pictureBox1.Update();//這句話相當關鍵  會是消除之前畫的圖 速度加快

            pictureBox1_ht();
}

 

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

 

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