public userchange()
{
InitializeComponent();
Userlist = new List <User>();
num = 1;
string conn = @"Data Source=WIN-M3MMPVP72UC;Initial Catalog=guanli;User ID=sa;Pwd=a"; //采取用户名登录数据库，.\SQLExpress似乎也可以作为本地服务器名,(local)也可
sa = new UsertoContext(conn);
}
public userchange(string user)
{
InitializeComponent();
Userlist = new List <User>();
num = 1;
string conn = @"Data Source=WIN-M3MMPVP72UC;Initial Catalog=guanli;integrated security=true"; //分别表示服务器名、数据库名、集成安全性，默认用windows账户登录
sa = new UsertoContext(conn);
user1 = user;
}
