SessionA和pplication网上聊天室的网络范例

login.aspx码，如以下：

<%@ Page Language=”C#” AutoEventWireup=”true” CodeFile=”Sample_chat_login.aspx.cs” Inherits=”Sample_chart_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></title>
    <style type=”text/css” >
        body { width:780px; margin:0px auto;}
        form { width:400px; margin:0px auto;}
        h3 { margin:10px; padding:10px; text-align:center;}
        p.tc { text-align:center; }
        
    
    </style>
</head>
<body>
    <form id=”form1″ runat=”server” defaultbutton=”Button1″ defaultfocus=”txt_id”>
    <div>
        <h3>聊天室登录</h3>

        <div>
            <p class=”tc”>
                <span >username：</span>
                <asp:TextBox ID=”txt_id” runat=”server”></asp:TextBox>    </p>
        
            <p  class=”tc”>
                <asp:Button ID=”Button1″ runat=”server” Text=”登录聊天室” onclick=”Button1_Click” />
            </p>
        </div>
    
    </div>
    </form>
</body>
</html>

login.aspx.cs代码例如以下：

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

public partial class Sample_chart_login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        //记录session: 当前username
        //跳转至聊天室页面
        if (txt_id.Text != "") {
            Session["s_id"] = txt_id.Text;
            Server.Transfer("Sample_chat_room.aspx");
        }
    }
}

room.aspx代码例如以下：

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

<!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></title>
    
    <style type=”text/css” >
        body { width:780px; margin:0px auto;}
       
        h3 { margin:10px; padding:10px; text-align:center;}
        p.tc { text-align:center; }
        
        #pnl_chat 
            { margin:10px; padding:10px;
              border:1px solid #dadada;
              height:300px;
                }
        #div_ctls
            { margin:10px; padding:10px;
              border:1px solid #dadade;
                }
    </style>

</head>
<body >
    <form id=”form1″ runat=”server” defaultbutton=”Button1″ defaultfocus=”txt_word”>
    <div>
    <h3>简易聊天室</h3>
    
    <asp:Panel ID=”pnl_chat” runat=”server” ScrollBars=”Vertical”>
    </asp:Panel>
    
    <div id=”div_ctls”>
        <p>
        <asp:TextBox ID=”txt_word” runat=”server” Width=”400″></asp:TextBox>
        <asp:Button ID=”Button1″ runat=”server” Text=”发送” onclick=”Button1_Click” />
        &nbsp;
            <asp:Button ID=”Button2″ runat=”server” Text=”刷新聊天记录”  />
         &nbsp;
            <asp:Button ID=”Button4″ runat=”server” Text=”清空” onclick=”Button4_Click”  />
        &nbsp;
            <asp:Button ID=”Button3″ runat=”server” Text=”退出聊天” onclick=”Button3_Click” />
        </p>

   <p>
        <span>选择我的颜色：</span>
        
        <asp:DropDownList ID=”ddl_color” runat=”server”>
            <asp:ListItem Value=”#666666″>默认</asp:ListItem>
            <asp:ListItem Value=”red”>红色</asp:ListItem>
            <asp:ListItem Value=”green”>绿色</asp:ListItem>
            <asp:ListItem Value=”blue”>蓝色</asp:ListItem>
        </asp:DropDownList>

        </p>
    </div>

    </div>
    </form>
</body>
</html>

room.aspx.cs代码例如以下：

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

public partial class Sample_chat_room : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //检測session是否存在，假设没有session值，返回登录页面
        if (Session["s_id"] == "" || Session["s_id"] == null) {
            Response.Redirect("Sample_chat_login.aspx");
        }


        

            //假设还没有Application["chat"]则创建。假设有则写入panel
            if (Application["chat"] != null)
            {
                pnl_chat.Controls.Add((Panel)Application["chat"]);
            }
            else
            {
                Panel _pnl = new Panel();
                Application["chat"] = _pnl;
            }
        

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        if(txt_word.Text !="") { // 注意：实际应用中，文本框是否为空，都应在前台进行检測；

        Label lab_name = new Label();
        lab_name.Text = Session["s_id"].ToString() + "[" + DateTime.Now.ToLongTimeString() + "]:";

        Label lab_word = new Label();
        lab_word.Style.Add("color", ddl_color.SelectedValue);
        lab_word.Text = txt_word.Text;

        Literal br = new Literal();
        br.Text = "<br/>";

        Panel _apppnl = (Panel)Application["chat"];
        _apppnl.Controls.AddAt(0, br);
        _apppnl.Controls.AddAt(0, lab_word);
        _apppnl.Controls.AddAt(0, lab_name);
            
        //_apppnl.Controls.Add(lab_name);
        //_apppnl.Controls.Add(lab_word);
        //_apppnl.Controls.Add(br);

        Application.Lock();
        Application["chat"] = _apppnl;
        Application.UnLock();

         

        //清空文本框
        txt_word.Text = "";

        pnl_chat.Controls.Add((Panel)Application["chat"]);
        

        }
    }
    protected void Button3_Click(object sender, EventArgs e)
    {
        Session.Remove("s_id");
        Response.Redirect("Sample_chat_login.aspx");

    }
    protected void Button2_Click(object sender, EventArgs e)
    {

    }
    protected void Button4_Click(object sender, EventArgs e)
    {
        Application.Lock();
        Application.Remove("chat");
        Application.UnLock();

        Server.Transfer("Sample_chat_room.aspx");
    }
}