用于绘制图形和滚动的面板 [英] Panel for drawing graphics and scrolling

问题描述

我希望能够使用Panel或类似方式将图形绘制到Winform上.如果图形变得比控件大，我似乎看不到任何有关添加滚动条的信息?

I want to be able to use a Panel or similar to draw graphics onto a Winform. I cannot seem to see anything regarding adding scrollbars if the graphics become larger than the control?

是否可以通过Panel来执行此操作，或者是否有类似的控件允许这样做?

Is it possible to do this with a Panel or is there a similar control that will allow it?

推荐答案

将AutoScroll属性设置为true，将AutoScrollMinSize属性设置为图像的大小.现在，当图像太大时，滚动条将自动出现.

Set the AutoScroll property to true and the AutoScrollMinSize property to the size of the image. The scrollbars will now automatically appear when the image is too large.

您将要从Panel继承您自己的类，以便可以在构造函数中将DoubleBuffered属性设置为true.否则，闪烁会很明显.一些示例代码:

You'll want to inherit your own class from Panel so that you can set the DoubleBuffered property to true in the constructor. Flicker would be noticeable otherwise. Some sample code:

using System;
using System.Drawing;
using System.Windows.Forms;

class ImageBox : Panel {
    public ImageBox() {
        this.AutoScroll = true;
        this.DoubleBuffered = true;
    }
    private Image mImage;
    public Image Image {
        get { return mImage; }
        set {
            mImage = value;
            if (value == null) this.AutoScrollMinSize = new Size(0, 0);
            else {
                var size = value.Size;
                using (var gr = this.CreateGraphics()) {
                    size.Width = (int)(size.Width * gr.DpiX / value.HorizontalResolution);
                    size.Height = (int)(size.Height * gr.DpiY / value.VerticalResolution);
                }
                this.AutoScrollMinSize = size;
            }
            this.Invalidate();
        }
    }
    protected override void OnPaint(PaintEventArgs e) {
        e.Graphics.TranslateTransform(this.AutoScrollPosition.X, this.AutoScrollPosition.Y);
        if (mImage != null) e.Graphics.DrawImage(mImage, 0, 0);
        base.OnPaint(e);
    }
}

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