如何在Picturebox上留下照片？

I am drawing a graph on a picturebox on Windows Mobile Smart Device Application. The graph works well, but it disappears immediately afterwards.

我正在Windows Mobile智能设备应用程序上的图片框上绘制图表。该图表效果很好，但之后会立即消失。

I used the line:

我用了这句话：

this.Invoke(new EventHandler(picture2_show));

and my drawing method:

和我的绘图方法：

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]);
        }
    }
}

The picturebox stays, but how do I make the graph not disappear??

图片框保持不变，但如何让图表不会消失？

Help is very much appreciated!

非常感谢帮助！

1 个解决方案

#1

You need to draw your graph in the picturebox's Paint event, using e.Graphics.
To force it to redraw, call pictureBox2.Invalidate().

您需要使用e.Graphics在图片框的Paint事件中绘制图形。要强制重绘，请调用pictureBox2.Invalidate（）。

Do not draw on CreateGraphics(), since it will be erased when the control is next painted.

不要在CreateGraphics（）上绘图，因为下次绘制控件时它将被删除。

#1