c# 泛型和委托

List<T> lst=new List<T>();
 List<T> l=lst.FindAll(delegate(T t){return t.name.Contains("a");});
 或使用LINQ

private  void button1_Click(object sender, EventArgs e)
         {
             List<string> myList = new List<string>();
             for(int i = 0; i < 10; i++)
             {
                 myList.Add(i.ToString ());//我给他填充1--10
            }

             if (myList.Find(MathChar) != null)
             {
                 MessageBox.Show("有这个元素");
             }
             else
             {
                 MessageBox.Show("没有这个元素");
             }
         }


         private bool MathChar(string str)
         {

             if (str.Equals("3"))//这里来判断是否有3这个元素
                return true;
             else
                 return false;
         }

自定义比较器器c#
 class userinfo
         {
             public string userno;
             public string username;
         }
         class UserComparer<T> : IEqualityComparer<T> where T : userinfo
         {            #region IEqualityComparer<T> Members
            public bool Equals(T x, T y)
             {
                 return x.username == y.username;
             }            public int GetHashCode(T obj)
             {
                 return obj.username.GetHashCode();
             }            #endregion
         }            List<userinfo> infos = new List<userinfo>();
             infos.Add(new userinfo() { userno = "001", username = "张某" });
             if (infos.Contains(new userinfo() { username = "张某" }, new UserComparer<userinfo>()))
                 MessageBox.Show("找到该用户");

sing System.Collections;
 using System.Collections.Generic;
 using System.Linq;

 var list=new List<string>();
 list.Where(x=>{
 if(x=="")
 {
 return true;
 }
 else
 {
 return false;……