如何使用Graphics类在PictureBox控件内绘制矩形? [英] How do i draw rectangle inside picturebox control using Graphics class?

问题描述

我想在知道图片框控件内的欧姆值后绘制电阻器图像.我无法访问图片框内的creategraphics.我怎么做?请帮忙.

i want to draw a resistor image after knowing a value in ohm inside a picturebox control. i cannnot access creategraphics inside picture box. how do i do that? please help.

推荐答案

您应该使用PictureBox.Image的Graphics，而不是Picturebox本身.像这样:

You should use the Graphics of the PictureBox.Image, not of the Picturebox itself. Like this:

Graphics g = Graphics.FromImage(pictureBox1.Image);

您可以简单地将PictureBox 类子类化并使用它.
对OnPaint方法的重写应允许您绘制所需的任何内容.

这样的事情应该可以解决问题:

You could simply subclass the PictureBox class and use that.
An override on the OnPaint method should allow you to draw whatever you want.

Something like this should do the trick:

class CustomPictureBox : PictureBox
{
    protected override void OnPaint(PaintEventArgs pe)
    {
        base.OnPaint(pe);

        pe.Graphics.DrawRectangle(Pens.Aquamarine, new Rectangle(0, 0, 4, 4));
    }
}

希望这会有所帮助，
弗雷德里克·博纳德(Fredrik Bornander)

Hope this helps,
Fredrik Bornander

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