ToDictionary

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"}
};
//使用LINQ查找用户代码大于2的列表
//此时的query变量的类型是IEnumerable<UserInfo>类型
var query = from item in users
                 where item.UserCode > 2
                 select item;
//使用ToDictionary方法将query转换为字典类型
Dictionary<int,UserInfo> userDict = query.ToDictionary(itm => itm.UserCode);

Response.Write("Dictionary的结果是：");
foreach (var user in userDict)
{
string temp = string.Format("(Key:{0},Value:{1})", user.Key, user.Value.UserName);
Response.Write(temp);
}

public class UserInfo
{
public UserInfo()
{
//
//TODO: 在此处添加构造函数逻辑
//
}

public int UserCode { get; set; }

public string UserName { get; set; }

public string Password { get; set; }

}