ASP.NET MVC 解决账号重复登录问题

解决重复登录 用到了 .net 身份票证 和Global全局处理文件 

第一步 登录方法  传入用户名

private void GetOnline(string Name)
{
Hashtable SingleOnline = (Hashtable)System.Web.HttpContext.Current.Application["Online"];
if (SingleOnline == null)
SingleOnline = new Hashtable();

//Session["mySession"] = "Test";
//SessionID
if (SingleOnline.ContainsKey(Name))
{
SingleOnline[Name] = Session.SessionID;
}
else
SingleOnline.Add(Name, Session.SessionID);


var httpCookie = new HttpCookie(FormsAuthentication.FormsCookieName);
var Expires = DateTime.Now.AddMinutes(30);
httpCookie.Expires = Expires;
httpCookie.Value = FormsAuthentication.Encrypt(new FormsAuthenticationTicket(0, Name, DateTime.Now, Expires, false, Name));
HttpContext.Response.Cookies.Add(httpCookie);


System.Web.HttpContext.Current.Application.Lock();
System.Web.HttpContext.Current.Application["Online"] = SingleOnline;
System.Web.HttpContext.Current.Application.UnLock();
}

　　

第二步  配置添加票证 和web.config

var httpCookie = new HttpCookie(FormsAuthentication.FormsCookieName);
var Expires = DateTime.Now.AddMinutes(30);
httpCookie.Expires = Expires;
httpCookie.Value = FormsAuthentication.Encrypt(new FormsAuthenticationTicket(0, Name, DateTime.Now, Expires, false, Name));
HttpContext.Response.Cookies.Add(httpCookie);

　　

身份票证可以放到底层封装起来 用于存储用用户名和票证信息 

添加完票证信息后 可能会出现User.Identity.Name 无法获取到值的问题，这个时候  就说明你web.config中未配置相应的参数

配置如下 在 <system.web>节点下配置 如下即可

<authentication mode="Forms">
<forms loginUrl="/" timeout="30" />
</authentication>
<authorization>
<allow users="*" />
</authorization>

　　

第三步 新建一个类配置mvc的过滤类

public class LoginActionFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
Hashtable singleOnline = (Hashtable)filterContext.HttpContext.Application["Online"];
// 判断当前SessionID是否存在
if (singleOnline != null && singleOnline.ContainsKey(filterContext.HttpContext.User.Identity.Name))
{
if (!singleOnline[filterContext.HttpContext.User.Identity.Name].Equals(filterContext.HttpContext.Session.SessionID))
{
filterContext.Result = new ContentResult() { Content = "<script>if(confirm('你的账号已在别处登陆，是否返回登陆页面重新登陆？')){window.location.href='/';}else{window.close();}</script>" };
}
}
base.OnActionExecuting(filterContext);
}
}

　　

将这串代码引入你的过滤类中即可 然后就OK了 该过滤器用于判断是否存在重复登录的情况，过滤器怎么用这里就不多说了，若存在重复登录，则执行if语句内的处理方式，这里的处理方式是弹出个确认框，当然你也可以直接跳转到登录地址，看需要更改。

 第四步 就是解决 资源释放问题 将如下代码放入 Global.asax 全局配置文件中

protected void Session_End()
{
Hashtable SingleOnline = (Hashtable)System.Web.HttpContext.Current.Application["Online"];
if (SingleOnline != null && SingleOnline[User.Identity.Name] != null)
{
SingleOnline.Remove(Session.SessionID);
System.Web.HttpContext.Current.Application.Lock();
System.Web.HttpContext.Current.Application["Online"] = SingleOnline;
System.Web.HttpContext.Current.Application.UnLock();
}
Session.Abandon();
}