泛型的小例子,C#3.5版

using  System; using  System.Collections.Generic; using  System.ComponentModel; using  System.Data; using  System.Drawing; using  System.Linq; using  System.Text; using  System.Windows.Forms; namespace  Comb {      public   partial   class  Form1 : Form     {          public  Form1()         {             InitializeComponent();         }          private   void  addSt()         {             List < ComboBoxItem < Student >>  list  =   new  List < ComboBoxItem < Student >> ();             list.Add( new  ComboBoxItem < Student > ( "" ,  null ));             Student s1  =   new  Student( " 张三 " ,  15 );             Student s2  =   new  Student( " 李四 " ,  20 );             list.Add( new  ComboBoxItem < Student > (s1.Name, s1));             list.Add( new  ComboBoxItem < Student > (s2.Name, s2));              // 绑定下拉框             comboBox1.DataSource  =  list;             comboBox1.DisplayMember  =   " ItemText " ;             comboBox1.ValueMember  =   " ItemValue " ;         }          private   void  comboBox1_SelectedIndexChanged( object  sender, EventArgs e)         {              // addSt();              if  (comboBox1.SelectedIndex  >   0 )             {                 Student s  =  (Student)comboBox1.SelectedValue;                 MessageBox.Show(s.Age.ToString());             }         }          private   void  button1_Click( object  sender, EventArgs e)         {                      }          private   void  Form1_Load( object  sender, EventArgs e)         {             addSt();         }     }      public   class  ComboBoxItem < T >     {          // ItemText显示的文字         //  private string _itemText;          public   string  ItemText         {              get ; set ;              // get { return _itemText ; }              // set { _itemText = value; }         }          // ItemValue实际的值         //  private T _itemValue;          public  T ItemValue         {              get ; set ;              // get { return _itemValue; }              // set { _itemValue = value; }         }          // 构造方法          public  ComboBoxItem( string  itemText, T itemValue)         {              // this._itemText = itemText;              // this._itemValue = itemValue;             ItemText  =  itemText;             ItemValue  =  itemValue;         }          // 自定义方法          // 确定指定的对象是否等于当前对象          public   override   bool  Equals( object  obj)         {             //  2643993              if  (obj  is  ComboBoxItem < T > )             {                 ComboBoxItem < T >  rhs  =  (ComboBoxItem < T > )obj;                 //  if (_itemText.Equals(rhs.ItemText) && _itemValue.Equals(rhs.ItemValue))                  if (ItemText.Equals(rhs.ItemText) && ItemValue.Equals(rhs.ItemValue))                      return   true ;                  else                      return   false ;             }              else                  return   false ;         }          // 获取当前对象的哈希代码          public   override   int  GetHashCode()         {              return  ItemText.GetHashCode()  +  ItemValue.GetHashCode();         }          // 重载相等操作符          public   static   bool   operator   == (ComboBoxItem < T >  lhs, ComboBoxItem < T >  rhs)         {  return  lhs.Equals(rhs); }          // 重载不等          public   static   bool   operator   != (ComboBoxItem < T >  lhs, ComboBoxItem < T >  rhs)         {  return   ! (lhs.Equals(rhs)); }     }      // 学生对象      public   class  Student     {          // 姓名          private   string  _name;          public   string  Name         {  get  {  return  _name; } }          // 年龄          private   int  _age;          public   int  Age         {  get  {  return  _age; } }          // 构造方法          public  Student( string  name,  int  age)         {             _name  =  name;             _age  =  age;         }     } }

转载于:https://www.cnblogs.com/wind8250/archive/2008/05/13/1194917.html