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");
}
}


privatebool MathChar(string str)
{

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

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

var list=new List<string>();
list.Where(x=>{
if(x=="")
{
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");