//构造序列

List<UserInfo> users = new List<UserInfo> {

new UserInfo{UserCode=1, UserName="User001", Password="001"},

new UserInfo{UserCode=2, UserName="User002", Password="002"},

new UserInfo{UserCode=3, UserName="User003", Password="003"},

new UserInfo{UserCode=4, UserName="User004", Password="004"}

};

//判断序列中所有元素的UserCode属性都大于1

bool isAll = users.All(itm => itm.UserCode > 1); //isAll=false

//判断序列中是否存在UserCode属性>=4的元素

bool isAny = users.Any(itm => itm.UserCode >= 4);//isAny=true

UserInfo tempUser = users[3];

//判断序列中是否包含tempUser元素

bool isContains = users.Contains(tempUser); //isContains=true

//输出结果

Response.Write(string.Format("All:{0} Any:{1} Contains:{2}",isAll,isAny,isContains));