如何有效防止同一账户去重复登录系统

2008-02-23 07:12:51来源：互联网阅读 ()

维护一Online表，查看有登录，就不允许再次登录，以Sessionid作为唯一标识符号，也可以产生一个GUID发到COOKIE中，以区分不同的CLIENT，再加上JS，可以达到更好的效果，比如离开后自动离线。

解决代码如下：

public virtual void Application_Start(object sender, EventArgs e) 

{ 

// reset the mailer indicator 

Application["MailerStatus"] = "All Mailings Complete"; 



// initialize a datatable for users online 

DataTable objUserTable = new DataTable(); 

objUserTable.Columns.Add("SessionID",System.Type.GetType("System.Guid")); 

objUserTable.Columns.Add("PeopleID",System.Type.GetType("System.Int32")); 

objUserTable.Columns.Add("ShowDetail",System.Type.GetType("System.Boolean")); 

DataColumn[] pk = new DataColumn[1]; 

pk[0] = objUserTable.Columns[0]; 

objUserTable.PrimaryKey = pk; 

Application["UserTable"] = objUserTable; 

} 



/**//// 

/// The Session_Start event adds user session information to 

/// Application["UserTable"]. 

/// 

public virtual void Session_Start(object sender, EventArgs e) 

{ 

Application.Lock(); 

//Application.Lock (); 

DataTable objUserTable = (DataTable)Application["UserTable"]; 

DataRow objRow = objUserTable.NewRow(); 

Guid objGuid = Guid.NewGuid(); 

objRow[0] = objGuid; 

Session["PfSessionID"] = objRow[0]; 

objRow[1] = 0; 

objRow[2] = false; 

objUserTable.Rows.Add(objRow); 

Application["UserTable"] = objUserTable; 

Application.UnLock(); 

} 





/**//// 

/// The Session_End event deletes user session information from 

/// Application["UserTable"]. 

/// 

public virtual void Session_End(object sender, EventArgs e) 

{ 

Application.Lock(); 

DataTable objUserTable = (DataTable)Application["UserTable"]; 

objUserTable.Rows.Find((Guid)Session["PfSessionID"]).Delete(); 

Application["UserTable"] = objUserTable; 

Application.UnLock(); 

}