聊天室

登錄頁面

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

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

    }
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        //1.判斷用戶名密碼是否正確，2.給服務器寫cookie 存用戶名但是不存密碼
        if (txtloginId.Text != "")
        {
            HttpCookie user = new HttpCookie("user");
            user["name"] = txtloginId.Text;
            user.Expires = DateTime.Now.AddDays(5);
            Response.Cookies.Add(user);//寫到Respon中，由他寫入瀏覽器
           
            //2.存登錄時間
            HttpCookie loginTime = new HttpCookie("time");
            loginTime["lastTime"] = DateTime.Now.ToShortDateString();
            user.Expires = DateTime.Now.AddDays(5);
            Response.Cookies.Add(loginTime);
            
            //3.跳轉頁面
            Response.Redirect("Main.aspx");
        }
    }
}

（登錄頁面沒有問題）

主頁面

（還包含發送消息和展示消息，此處主要接收用戶名和登錄時間）

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Main : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        HttpCookie user = Request.Cookies["user"];
        if (user != null)
        {
            String name = user["name"];
            lblLoginDate.Text = name + " welcome  ";
        }

        HttpCookie loginTime = Request.Cookies["time"];
        if (loginTime != null)
        {
            String time = loginTime["lastTime"];
            lblLoginDate.Text = lblLoginDate.Text +"login time"+ time;
        }
    }
}

發送消息

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

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

    }
    protected void btnSendMessage_Click(object sender, EventArgs e)
    { 
        HttpCookie user = Request.Cookies["user"];
        if (user != null)
        {
            string name = user["name"].ToString() ;
            string mess = txtMessage.Text.ToString();
            Application.Lock();
            Application["name"]= name;
            Application["mess"] = mess;
            Application.UnLock();
        } 
    }
}

展示消息

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class ShowMessage : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Application.Lock();//一定要寫
        string name = Application["name"].ToString();
        string mess = Application["mess"].ToString();
        Application.UnLock();
        txtShowMessage.Text += name + "說：" + mess+"\n"; 
    }
}

剛開始沒寫Lock和UnLock，一直報錯“未將對象引用設置到對象的實例”，搜半天都說是取不到值，沒改好突然想到Lock和UnLock,加上之後消息可以顯示了但是需要刷新而且只顯示最新一條