在ASP.NET中每个用户仅限制一个会话

Question

无论如何检测用户何时登录是否已经有另一个具有相同用户名的会话,并阻止他再次登录或向他发送消息？

Answer 1

您始终可以在global.asax中实现事件.

实现Application_Start()以设置System.Collections.Dictionary(或根据您的喜好)并将其存储在Application []集合中,当用户登录时,添加用户名.从Session_End()中的集合中删除.在使用集合时,请记住使用'lock'关键字:)

玩得开心!

例:

[page.aspx]
public partial class page : System.Web.UI.Page {
    protected bool Login(string userName) {
        System.Collections.Generic.List<string> d = Application["UsersLoggedIn"]
            as System.Collections.Generic.List<string>;
        if (d != null) {
            lock (d) {
                if (d.Contains(userName)) {
                    // User is already logged in!!!
                    return false;
                }
                d.Add(userName);
            }
        }
        Session["UserLoggedIn"] = userName;
        return true;
    }

    protected void Logout() {
        Session.Abandon();
    }
}

[global.asax]
<%@ Application Language="C#" %>
<script RunAt="server">
    void Application_Start(object sender, EventArgs e) {
        Application["UsersLoggedIn"] = new System.Collections.Generic.List<string>();
    }

    void Session_End(object sender, EventArgs e) {
        // NOTE: you might want to call this from the .Logout() method - aswell -, to speed things up
        string userLoggedIn = Session["UserLoggedIn"] == null ? string.Empty ? (string)Session["UserLoggedIn"];
        if (userLoggedIn.Length > 0) {
            System.Collections.Generic.List<string> d = Application["UsersLoggedIn"] 
                as System.Collections.Generic.List<string>;
            if (d != null) {
                lock (d) {
                    d.Remove(userLoggedIn);
                }
            }
        }
    }
</script>