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asp?url=/library/en-us/cpref/html/frlrfsystemcollectionscollectionbaseclasstopic.asp">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;
       ///
       /// ButtonArray 的摘要说明。
       ///
       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();
              }
       }
}