使用Visual Studio 2010继承Windows窗体类

Question

我正在使用Visual Studio 2010创建应用程序。 我有一个派生自System.Windows.Forms.Form控件的类。 此类称为CViewport，是我的应用程序中所有形式的标准（即，我打算从此类中派生其他形式）。

从CViewport派生一个类之后，我去设计器编辑第二代表单，并且在设计器中该表单无法正确显示。 如果我没记错的话，它看起来是透明的...上一个窗口在表单的客户区域闪闪发光，就好像设计师没有绘制后缓冲...

...此外，在更改了第二代表格的大小后，设计人员将大小重置为任意尺寸...

为什么会这样呢？ 这是Form派生类：

namespace MyApp
{
    public partial class CViewport : Form
    {
        public CViewport()
        {
            InitializeComponent();

        }
    }
}

这是CViewport.Designer.cs：

namespace MyApp
{
    partial class CViewport
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(GDEViewport));
            this.SuspendLayout();
            // 
            // CViewport
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 600);
            this.ControlBox = false;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;
            this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
            this.MaximizeBox = false;
            this.MinimizeBox = false;
            this.Name = "GDEViewport";
            this.ShowIcon = false;
            this.ShowInTaskbar = false;
            this.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Hide;
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
            this.Activated += new System.EventHandler(this.ViewportForm_Activated);
            this.Deactivate += new System.EventHandler(this.ViewportForm_Deactivate);
            this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.OnFormClosing);
            this.ResizeBegin += new System.EventHandler(this.ViewportForm_ResizeBegin);
            this.ResizeEnd += new System.EventHandler(this.ViewportForm_ResizeEnd);
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.ViewportForm_Paint);
            this.Resize += new System.EventHandler(this.MainViewport_UserResized);
            this.ResumeLayout(false);

        }

        #endregion
    }
}

这是从CViewport衍生的第二代表格

namespace MyApp
{
    public partial class CMainViewport: CViewport
    {
        public CMainViewport()
        {
            InitializeComponent();
        }
    }
}

这是CMainViewport.Designer.cs：

namespace MyApp
{
    partial class CMainViewport
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // CMainViewport
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(1218, 573);
            this.ControlBox = true;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;
            this.MaximizeBox = true;
            this.MinimizeBox = true;
            this.MinimumSize = new System.Drawing.Size(800, 600);
            this.Name = "TestForm";
            this.RightToLeft = System.Windows.Forms.RightToLeft.No;
            this.ShowIcon = true;
            this.ShowInTaskbar = true;
            this.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Auto;
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "TestForm";
            this.PauseRendering += new System.EventHandler<System.EventArgs>(this.ViewportForm_PauseRendering);
            this.ResumeRendering += new System.EventHandler<System.EventArgs>(this.ViewportForm_ResumeRendering);
            this.SystemResume += new System.EventHandler<System.EventArgs>(this.MainViewport_SystemResume);
            this.SystemSuspend += new System.EventHandler<System.EventArgs>(this.MainViewport_SystemSuspend);
            this.UserResized += new System.EventHandler<System.EventArgs>(this.MainViewport_UserResized);
            this.Activated += new System.EventHandler(this.ViewportForm_Activated);
            this.Deactivate += new System.EventHandler(this.ViewportForm_Deactivate);
            this.ResizeBegin += new System.EventHandler(this.ViewportForm_ResizeBegin);
            this.ResizeEnd += new System.EventHandler(this.ViewportForm_ResizeEnd);
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.ViewportForm_Paint);
            this.Resize += new System.EventHandler(this.ViewportForm_Resize);
            this.ResumeLayout(false);

        }

        #endregion
    }
}

Answer 1

  this.ResizeBegin += new System.EventHandler(this.ViewportForm_ResizeBegin);
  this.ResizeEnd += new System.EventHandler(this.ViewportForm_ResizeEnd);
  this.Paint += new System.Windows.Forms.PaintEventHandler(this.ViewportForm_Paint);
  this.Resize += new System.EventHandler(this.MainViewport_UserResized);

设计器在基类中运行代码以提供WYSIWYG视图。 那通常是Form类，没有任何错误。 现在是您的CViewPort类。 它有错误。 在其中一种我们看不到的事件处理程序中。

类似于Paint事件处理程序，强烈导致“未正确显示”。 您有一个“调整大小”处理程序，可以很强地导致“将大小重置为任意尺寸”。 在设计时运行这些事件也会使您陷入麻烦。 而且您做错了，Form的基类应该重写OnPaint（）和OnResize（），因此代码的运行顺序是可预测和可控制的。

在设计时运行代码需要对Winforms的工作方式有更深入的了解，因此从书中获得指导非常重要。 您还没有到那儿，您还没有意识到发布这些事件处理程序的代码甚至相关。 有一种避免麻烦的方法，可以让您有时间阅读本书，将以下代码行添加到添加到CViewPort类的每个事件处理程序中：

  if (this.DesignMode) return;

Answer 2

汉斯·帕桑特（Hans Passant）发布的答案非常有帮助...不过，问题是，我在基本表单的构造函数中将基类的DockStyle属性设置为“填充”。 删除此行代码可解决问题...