永远不会调用OnPaint覆盖

本文介绍了永远不会调用OnPaint覆盖的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我已经待了几天，这让我发疯了.我有一个继承自System.Windows.Forms.Panel的控件，并且我试图覆盖OnPaint.只是简单而直接地忽略它.

I have been at this for a few days and it is driving me mad. I have a control that inherits from System.Windows.Forms.Panel and I'm trying to override OnPaint. It just plain, outright IGNORES it.

public class CollapsiblePanel : System.Windows.Forms.Panel { public CollapsiblePanel() { // // Required for the Windows Form Designer // InitializeComponent(); // // TODO: Add any constructor code after InitializeComponent call // SetStyle ( ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.DoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.Selectable , true ); } protected override void OnPaint(PaintEventArgs e) { // This never runs no matter what I try! base.OnPaint(e); } }

推荐答案

当我尝试覆盖OnPaint时，我只遇到一个ProgressBar的问题.它从未被调用.

I have the same problem just with a ProgressBar, when i try to override the OnPaint.. It's never called.

我在这里找到了解决方案: web.archive/web/20140214234801/osix/modules/article/?id=826

I found the solution here: web.archive/web/20140214234801/osix/modules/article/?id=826

您必须创建一个构造函数并启用用户绘画，如下所示:

You must create a constructor and enable user-painting like this:

SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw, true);

默认值可能会因框架版本和操作系统而异.

Default values, probably vary depending on framework version and OS.