.NET中添加控件数组

作者：cuike519的专栏   http://blog.csdn.net/cuike519/


添加控件数组

在.NET里面我好像没有找到有关于控件数组的说明,但是前两天偶在网上看到了一篇关于如何在.NET里面实现控件数组的文章(该文章请参看MSDN).记得大学的时候在使用VB的时候使用过控件数组,可是到了.NET的时代好像没有了.当时可以用控件数组作很多繁琐的事情,可以动态的生成一些功能和目的基本相同的一组文本框和一堆标签.这些控件数组响应同一个事件,我们在使用它的时候可以直接通过索引来访问.我使用.NET以后好像绑定让一切变的如此简单,好像控件数组没有什么用了,但是在前面的一次开发中我还是偶然的想到了使用控件数组,苦于不知道如何申明后来发现.NET不支持这个东东了.其实如果我们很了解FCL的话我想这个实现起来也不难!好了废话就不说了下面开始我们的创建工作.这次我们创建的是Button的数组(也是MSDN上的例子.本文的原型以及代码均来自MSDN,如果想要了解更多的详细信息请参考MSDN的帮助),首先我们用到了CollectionBase (请参考http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemcollectionscollectionbaseclasstopic.asp) 类,该类提供了一个抽象的强类型集合的基类.我们可以用它来实现我们的控件数组.首先我们需要建立一个从CollectionBase继承的类,我们称之为ButtonArray.用来做存放Button的容器.下面是实现的代码:

namespace ButtonArrayProject{

       using System;

       /// <summary>

       /// ButtonArray 的摘要说明。

       /// </summary>

       public class ButtonArray : System.Collections.CollectionBase{

              // 容器的一个引用,引用该控件数组所在的窗体的一个引用

              private readonly System.Windows.Forms.Form HostForm;

              // 添加一个新的按钮

              public System.Windows.Forms.Button AddNewButton(){

                     // 创建一个新的按钮实例

                     System.Windows.Forms.Button aButton = new System.Windows.Forms.Button();

                     // 将该新的控件添加到(this)列表中

                     this.List.Add(aButton);

                     // 将控件添加到父窗体的控件集合中

                     HostForm.Controls.Add(aButton);

                     // 设置该控件的属性

                     aButton.Top = Count * 25;

                     aButton.Left = 100;

                     // 用Button的Tag表示控件数组中的索引

                     aButton.Tag = this.Count;

                     aButton.Text = "Button " + this.Count.ToString();

                     // 添加一个事件响应

                     aButton.Click += new System.EventHandler(ClickHandler);

                     // 返回该新的控件

                     return aButton;

              }

              // 删除控件数组中的最后一个元素

              public void Remove(){

                     // 检测该控件数组中是否有控件

                     if(this.Count > 0){

                            // 如果有则先从父容器中删除最后一个元素

                            // 注意:此处是通过索引访问

                            this.HostForm.Controls.Remove(this[this.Count-1]);

                            // 删除控件数组中的最后一个控件

                            this.List.RemoveAt(this.Count-1);

                     }

              }

              // 添加一个事件出来函数

              public void ClickHandler(Object sender, System.EventArgs e) {

                     // 用MessageBox返回一条消息

                     System.Windows.Forms.MessageBox.Show("你点击的是 " +

                            ((System.Windows.Forms.Button) sender).Tag.ToString());

              }

              // 带父窗体引用的构造函数

              public ButtonArray(System.Windows.Forms.Form host){

                     // 为父窗体的引用赋值

                     this.HostForm = host;

                     // 添加一个默认的按钮

                     this.AddNewButton();

              }

              // 控件数组的索引可以利用索引访问(只能得到)

              public System.Windows.Forms.Button this[int index]{

                     get{

                            return (System.Windows.Forms.Button)this.List[index];

                     }

              }

       }

}

为了测试程序我们添加一个WinForm的工程.在该工程的Form1中放入两个Button用来添加或者删除控件数组中的控件.同时我们还需要在Form1中声明一个ButtonArray的对象.在Form1的构造函数中实例该对象, 代码如下:

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

namespace ButtonArrayProject

{

       public class Form1 : System.Windows.Forms.Form{

              private ButtonArray btnArray ;

              private System.Windows.Forms.Button btnAdd;

              private System.Windows.Forms.Button btnRemove;

              private System.ComponentModel.Container components = null;

              public Form1(){

                     InitializeComponent();

                     this.btnArray = new ButtonArray(this);

              }

              protected override void Dispose( bool disposing ){

                     if( disposing )

                     {

                            if (components != null)

                            {

                                   components.Dispose();

                            }

                     }

                     base.Dispose( disposing );

              }

              #region Windows

              private void InitializeComponent()     {

                     this.btnAdd = new System.Windows.Forms.Button();

                     this.btnRemove = new System.Windows.Forms.Button();

                     this.SuspendLayout();

                     //

                     // btnAdd

                     //

                     this.btnAdd.Location = new System.Drawing.Point(352, 136);

                     this.btnAdd.Name = "btnAdd";

                     this.btnAdd.Size = new System.Drawing.Size(112, 23);

                     this.btnAdd.TabIndex = 0;

                     this.btnAdd.Text = "AddNewButton";

                     this.btnAdd.Click += new System.EventHandler(this.btnAdd_Click);

                     //

                     // btnRemove

                     //

                     this.btnRemove.Location = new System.Drawing.Point(352, 192);

                     this.btnRemove.Name = "btnRemove";

                     this.btnRemove.Size = new System.Drawing.Size(112, 23);

                     this.btnRemove.TabIndex = 1;

                     this.btnRemove.Text = "RemoveButton";

                     this.btnRemove.Click += new System.EventHandler(this.btnRemove_Click);

                     //

                     // Form1

                     //

                     this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);

                     this.ClientSize = new System.Drawing.Size(512, 381);

                     this.Controls.Add(this.btnRemove);

                     this.Controls.Add(this.btnAdd);

                     this.Name = "Form1";

                     this.Text = "Form1";

                     this.ResumeLayout(false);

              }

              #endregion

              [STAThread]

              static void Main() {

                     Application.Run(new Form1());

              }

              private void btnAdd_Click(object sender, System.EventArgs e) {

                     this.btnArray.AddNewButton();

// 这里就是通过索引访问的实例

                     this.btnArray[0].BackColor = Color.Blue;

              }

              private void btnRemove_Click(object sender, System.EventArgs e) {

                     this.btnArray.Remove();

              }

       }

}