網上看到很多單點登錄的原理和實例，講的像廣告一樣。哎，我看了好幾天還是看不明白。但是項目需要這個功能，于是，我自己做了一個。發布出來，希望像我一樣的需求的人能早些解決問題。

思路：使用第三方認證。那么就要用到跨域訪問（就是變量要在不同ip地址下實現訪問），大白話說，就是網絡訪問。我不會Socket,就用Remoting吧！（Application不可以，因為它不能跨主機）

看代碼：

1，建類庫StatusService，在它里面建類LoginList

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace StatusService
{
??? public class LoginList : MarshalByRefObject, IList
??? {
??????? private object[] _contents = new object[8];
??????? private int _count;

??????? public LoginList()
??????? {
??????????? _count = 0;
??????? }

??????? // IList Members
??????? public int Add(object value)
??????? {
??????????? if (_count < _contents.Length)
??????????? {
??????????????? _contents[_count] = value;
??????????????? _count++;

??????????????? return (_count - 1);
??????????? }
??????????? else
??????????? {
??????????????? return -1;
??????????? }
??????? }

??????? public void Clear()
??????? {
??????????? _count = 0;
??????? }

??????? public bool Contains(object value)
??????? {
??????????? bool inList = false;
??????????? for (int i = 0; i < Count; i++)
??????????? {
??????????????? if (_contents[i] == value)
??????????????? {
??????????????????? inList = true;
??????????????????? break;
??????????????? }
??????????? }
??????????? return inList;
??????? }

??????? public int IndexOf(object value)
??????? {
??????????? int itemIndex = -1;
??????????? for (int i = 0; i < Count; i++)
??????????? {
??????????????? if (_contents[i] == value)
??????????????? {
??????????????????? itemIndex = i;
??????????????????? break;
??????????????? }
??????????? }
??????????? return itemIndex;
??????? }

??????? public void Insert(int index, object value)
??????? {
??????????? if ((_count + 1 <= _contents.Length) && (index < Count) && (index >= 0))
??????????? {
??????????????? _count++;

??????????????? for (int i = Count - 1; i > index; i--)
??????????????? {
??????????????????? _contents[i] = _contents[i - 1];
??????????????? }
??????????????? _contents[index] = value;
??????????? }
??????? }

??????? public bool IsFixedSize
??????? {
??????????? get
??????????? {
??????????????? return true;
??????????? }
??????? }

??????? public bool IsReadOnly
??????? {
??????????? get
??????????? {
??????????????? return false;
??????????? }
??????? }

??????? public void Remove(object value)
??????? {
??????????? RemoveAt(IndexOf(value));
??????? }

??????? public void RemoveAt(int index)
??????? {
??????????? if ((index >= 0) && (index < Count))
??????????? {
??????????????? for (int i = index; i < Count - 1; i++)
??????????????? {
??????????????????? _contents[i] = _contents[i + 1];
??????????????? }
??????????????? _count--;
??????????? }
??????? }

??????? public object this[int index]
??????? {
??????????? get
??????????? {
??????????????? return _contents[index];
??????????? }
??????????? set
??????????? {
??????????????? _contents[index] = value;
??????????? }
??????? }

??????? // ICollection Members

??????? public void CopyTo(Array array, int index)
??????? {
??????????? int j = index;
??????????? for (int i = 0; i < Count; i++)
??????????? {
??????????????? array.SetValue(_contents[i], j);
??????????????? j++;
??????????? }
??????? }

??????? public int Count
??????? {
??????????? get
??????????? {
??????????????? return _count;
??????????? }
??????? }

??????? public bool IsSynchronized
??????? {
??????????? get
??????????? {
??????????????? return false;
??????????? }
??????? }

??????? // Return the current instance since the underlying store is not
??????? // publicly available.
??????? public object SyncRoot
??????? {
??????????? get
??????????? {
??????????????? return this;
??????????? }
??????? }

??????? // IEnumerable Members

??????? public IEnumerator GetEnumerator()
??????? {
??????????? // Refer to the IEnumerator documentation for an example of
??????????? // implementing an enumerator.
??????????? throw new Exception("The method or operation is not implemented.");
??????? }

??????? public void PrintContents()
??????? {
??????????? Console.WriteLine("List has a capacity of {0} and currently has {1} elements.", _contents.Length, _count);
??????????? Console.Write("List contents:");
??????????? for (int i = 0; i < Count; i++)
??????????? {
??????????????? Console.Write(" {0}", _contents[i]);
??????????? }
??????????? Console.WriteLine();
??????? }

??? }
}

?2，建一個控制臺SSOService

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Remoting;

namespace SSOService
{
??? class MyServer
??? {
??????? [STAThread]
??????? static void Main(string[] args)
??????? {
??????????? RemotingConfiguration.Configure("SSOService.exe.config");
??????????? Console.ReadLine();
??????? }

??? }
}

配置文件是：

<configuration>
? <system.runtime.remoting>
??? <application name="SSOService">
????? <service>
??????? <wellknown type="StatusService.LoginList,StatusService" objectUri="StatusService.LoginList"
??????????? mode="Singleton" />
????? </service>
????? <channels>
??????? <channel ref="tcp" port="9999"/>
????? </channels>
??? </application>
? </system.runtime.remoting>
</configuration>

3，網站S1文件：

Default.aspx

Login.aspx

Web.config

（1）Default.aspx內容就是：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

<html xmlns=" http://www.w3.org/1999/xhtml ">
<head runat="server">
??? <title>S2</title>
</head>
<body>
??? <form id="form1" runat="server">
??? <div>
??? S2登陸成功！
??? </div>
??? </form>
</body>
</html>

實際使用按照需求自由調整。

（2）Login.aspx

前臺是：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Login.aspx.cs" Inherits="Login" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

<html xmlns=" http://www.w3.org/1999/xhtml ">
<head runat="server">
??? <title>S2</title>
</head>
<body>
??? <form id="form1" runat="server">
??? <div style="line-height:30px;">
??? <div>s2登陸界面</div>
??? 用戶：<asp:TextBox id="user" Text="abc" runat="server"></asp:TextBox><br />
??? 密碼：<asp:TextBox ID="pwd" Text="123" runat="server"></asp:TextBox><br />
??? <asp:Button ID="Button1" Text="登陸" OnClick="Button1_OnClick" runat="server" />
??? </div>
??? </form>
</body>
</html>

后臺是：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Login : System.Web.UI.Page
{
??? StatusService.LoginList ls = (StatusService.LoginList)Activator.GetObject(typeof(StatusService.LoginList), System.Configuration.ConfigurationSettings.AppSettings["ServiceURL"]);
??? protected void Page_Load(object sender, EventArgs e)
??? {
??????? Response.Write("記錄條數是：" + ls.Count.ToString() + "<br/>");
??????? for (int i = 0; i < ls.Count; i++)
??????? {
??????????? //Response.Write(ls[i] + "<br/>");
??????????? if (ls[i].ToString().Trim()=="abc")
??????????? {
??????????????? Response.Redirect("Default.aspx");
??????????? }

??????? }
??? }

??? protected void Button1_OnClick(object sender, EventArgs e)
??? {
??????? ls.Add("abc");
??????? Response.Redirect("Default.aspx");
??? }
}

（3）Web.config

<?xml version="1.0"?>
<configuration>
?<appSettings>
??<add key="ServiceURL" value="tcp://localhost:9999/StatusService.LoginList"/>
?</appSettings>
?<system.web>
??<compilation debug="true" targetFramework="4.0"/>
?</system.web>
</configuration>

4，再建一個S2,和S1一樣。

5，運行時要設置多項目運行，并且是最先運行SSOService。

完畢！

上敘是在vs2010上測試的。絕對簡單實用，沒有廣告！不實就砸我吧，我認！有好的建議希望多賜教！謝謝了！

單點登錄解決方案