如何使照片保持在Picturebox上？

Question

我正在Windows Mobile智能設備應用程序上繪製一個圖片框。該圖表運行良好，但之後立即消失。

我用行：

this.Invoke(new EventHandler(picture2_show)); 

和我的畫法：

private void picture2_show(object sender, EventArgs e) 
{ 
    using (Graphics objGraphics = this.pictureBox2.CreateGraphics()) 
    { 
     Pen redpen = new Pen(Color.Red, 1); 
     int picBoxWidth = pictureBox2.Size.Width; 
     int picBoxHeight = pictureBox2.Size.Height; 
     int halfWidth = pictureBox2.Size.Width/2; 
     int halfHeight = pictureBox2.Size.Height/2; 

     Graphics objGraphic = this.pictureBox2.CreateGraphics(); 

     objGraphic.DrawLine(redpen, 0, 0, 0, picBoxHeight); 
     objGraphic.DrawLine(redpen, 0, picBoxHeight - 1, picBoxWidth, picBoxHeight - 1); 
     //Rectangle first = new Rectangle(0, halfHeight, picBoxWidth, halfHeight); 

     Pen bpen = new Pen(Color.LawnGreen, 3); 
     for (int i = 0; i < array.Length - 1; i++) 
     { 
      objGraphic.DrawLine(
       bpen, 
       pictureBox2.Size.Width * i/array.Length, 
       pictureBox2.Size.Height - array[i], 
       pictureBox2.Size.Width * (i + 1)/array.Length, 
       pictureBox2.Size.Height - array[i + 1]); 
     } 
    } 
} 

PictureBox的停留，但如何使圖不會消失？

幫助非常感謝！

Answer 1

您需要在圖片框的Paint事件中使用e.Graphics繪製圖表。
要強制重繪，請撥打pictureBox2.Invalidate()。

不要在CreateGraphics()上畫，因爲當控件下一次繪製時它將被擦除。