我在ASP.NET网站上有一个聊天页面，我希望有一个代码可以在新消息到达数据库时自动更新聊天。我正在使用SQL，ASP.NET和C＃。
我尝试了一些代码，但由于需要而无法正常运行
<%@ Page Language="C#" AutoEventWireup="true"
CodeFile="allchats.aspx.cs" MaintainScrollPositionOnPostback="true"
Inherits="chat_allchats" %>
<link
href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css"
rel="stylesheet" id="bootstrap-css">
<script
src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<!DOCTYPE html>
<html>
<head>
<title>Chat</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/malihu-custom-scrollbar-plugin/3.1.5/jquery.mCustomScrollbar.min.css">
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/malihu-custom-scrollbar-plugin/3.1.5/jquery.mCustomScrollbar.min.js"></script>
<style>
body,html{
height: 100%;
margin: 0;
background: #7F7FD5;
background: -webkit-linear-gradient(to right, #91EAE4, #86A8E7, #7F7FD5);
background: linear-gradient(to right, #91EAE4, #86A8E7, #7F7FD5);
}
.chat{
margin-top: auto;
margin-bottom: auto;
}
.card{
height: 500px;
border-radius: 15px !important;
background-color: rgba(0,0,0,0.4) !important;
}
.contacts_body{
padding: 0.75rem 0 !important;
overflow-y: auto;
white-space: nowrap;
}
.msg_card_body{
overflow-y: auto;
}
.card-header{
border-radius: 15px 15px 0 0 !important;
border-bottom: 0 !important;
}
.card-footer{
border-radius: 0 0 15px 15px !important;
border-top: 0 !important;
}
.container{
align-content: center;
}
.search{
border-radius: 15px 0 0 15px !important;
background-color: rgba(0,0,0,0.3) !important;
border:0 !important;
color:white !important;
}
.search:focus{
box-shadow:none !important;
outline:0px !important;
}
.type_msg{
background-color: rgba(0,0,0,0.3) !important;
border:0 !important;
color:white !important;
height: 60px !important;
overflow-y: auto;
}
.type_msg:focus{
box-shadow:none !important;
outline:0px !important;
}
.attach_btn{
border-radius: 15px 0 0 15px !important;
background-color: rgba(0,0,0,0.3) !important;
border:0 !important;
color: white !important;
cursor: pointer;
}
.send_btn{
border-radius: 0 15px 15px 0 !important;
background-color: rgba(0,0,0,0.3) !important;
border:0 !important;
color: white !important;
cursor: pointer;
}
.search_btn{
border-radius: 0 15px 15px 0 !important;
background-color: rgba(0,0,0,0.3) !important;
border:0 !important;
color: white !important;
cursor: pointer;
}
.contacts{
list-style: none;
padding: 0;
}
.contacts li{
width: 100% !important;
padding: 5px 10px;
margin-bottom: 15px !important;
}
.active{
background-color: rgba(0,0,0,0.3);
}
.user_img{
height: 70px;
width: 70px;
border:1.5px solid #f5f6fa;
}
.user_img_msg{
height: 40px;
width: 40px;
border:1.5px solid #f5f6fa;
}
.img_cont{
position: relative;
height: 70px;
width: 70px;
}
.img_cont_msg{
height: 40px;
width: 40px;
}
.online_icon{
position: absolute;
height: 15px;
width:15px;
background-color: #4cd137;
border-radius: 50%;
bottom: 0.2em;
right: 0.4em;
border:1.5px solid white;
}
.offline{
background-color: #c23616 !important;
}
.user_info{
margin-top: auto;
margin-bottom: auto;
margin-left: 15px;
}
.user_info span{
font-size: 20px;
color: white;
}
.user_info p{
font-size: 10px;
color: rgba(255,255,255,0.6);
}
.video_cam{
margin-left: 50px;
margin-top: 5px;
}
.video_cam span{
color: white;
font-size: 20px;
cursor: pointer;
margin-right: 20px;
}
.msg_cotainer{
margin-top: auto;
margin-bottom: auto;
margin-left: 10px;
border-radius: 25px;
background-color: #82ccdd;
padding: 10px;
position: relative;
}
.msg_cotainer_send{
margin-top: auto;
margin-bottom: auto;
margin-right: 10px;
border-radius: 25px;
background-color: #78e08f;
padding: 10px;
position: relative;
}
.msg_time{
position: absolute;
left: 0;
bottom: -15px;
color: rgba(255,255,255,0.5);
font-size: 10px;
}
.msg_time_send{
position: absolute;
right:0;
bottom: -15px;
color: rgba(255,255,255,0.5);
font-size: 10px;
}
.msg_head{
position: relative;
}
#action_menu_btn{
position: absolute;
right: 10px;
top: 10px;
color: white;
cursor: pointer;
font-size: 20px;
}
.action_menu{
z-index: 1;
position: absolute;
padding: 15px 0;
background-color: rgba(0,0,0,0.5);
color: white;
border-radius: 15px;
top: 30px;
right: 15px;
display: none;
}
.action_menu ul{
list-style: none;
padding: 0;
margin: 0;
}
.action_menu ul li{
width: 100%;
padding: 10px 15px;
margin-bottom: 5px;
}
.action_menu ul li i{
padding-right: 10px;
}
.action_menu ul li:hover{
cursor: pointer;
background-color: rgba(0,0,0,0.2);
}
@media(max-width: 576px){
.contacts_card{
margin-bottom: 15px !important;
}
}
</style>
</head>
<body>
<form runat="server">
<% EccoSchoolEntities db = new EccoSchoolEntities();
string r = "",u="",n="",f="";
if(Session["role"]!=null && Session["user_id"]!=null )
{
r = Session["role"].ToString();
u = Session["user_id"].ToString();
if(r=="student" || r=="Teacher")
{
}else {
Response.Redirect("/login.aspx");
}
}
else
{
Response.Redirect("/login.aspx");
}
int uu = int.Parse(u);
// var j = db.messages.Any(a => a.reciever_id == uu);
// var x = (from s in db.messages where s.del == false && s.reciever_id == uu select new { s}).Count();
// var num = x.ToString();
%>
<div class="container-fluid h-100">
<div class="row justify-content-center h-100">
<div class="col-md-4 col-xl-3 chat">
<div class="card mb-sm-3 mb-md-0 contacts_card">
<div class="card-header">
<div class="input-group">
<%--<input type="text" placeholder="Search..." name="" onkeyup="myFunction1()" id="s1" class="form-control search">--%>
<%--<div class="input-group-prepend">
<span class="input-group-text search_btn"><i class="fas fa-search"></i></span>
</div>--%>
</div>
</div>
<%
var xx = (from s in db.chat where s.del == false && (s.reciever_id == uu ||s.sender_id==uu) select new { s}).ToList();
if (xx != null)
{
foreach (var item in xx)
{
DateTime d = DateTime.Parse(item.s.date.ToString());
%>
<div class="card-body contacts_body" id="mytable">
<ui class="contacts">
<li class="active">
<div class="d-flex bd-highlight">
<div class="img_cont">
<a href="allchats.aspx?s_id=<%=item.s.sender_id %>&&r_id=<%=item.s.reciever_id %>"><img src="../assets/img/1.png" class="rounded-circle user_img"/></a>
<span class="online_icon"></span>
</div>
<div class="user_info">
<%if (uu == item.s.reciever_id)
{ %>
<span><%=item.s.sender_name %></span>
<%}%>
<%else if (uu == item.s.sender_id)
{ %>
<span><%=item.s.reciever_name %></span>
<%} %>
<p> online</p>
</div>
<%}
} %>
</div>
</li>
</ui>
</div>
<div class="card-footer"></div>
</div></div>
<%
if (!String.IsNullOrEmpty(Convert.ToString(Request.QueryString["s_id"])) && !String.IsNullOrEmpty(Convert.ToString(Request.QueryString["r_id"])))
{
int s_id = int.Parse(Request.QueryString["s_id"].ToString());
int r_id = int.Parse(Request.QueryString["r_id"].ToString());
var xxc = (from s in db.messages where s.del == false && ((s.reciever_id == r_id && s.sender_id == s_id) ||(s.reciever_id == s_id && s.sender_id == r_id) ) select new { s }).Count();
var xx2 = (from s in db.chat where s.del == false && (s.reciever_id == r_id && s.sender_id == s_id) select s.reciever_name).FirstOrDefault();
var xx22 = (from s in db.chat where s.del == false && (s.reciever_id == r_id && s.sender_id == s_id) select s.sender_name).FirstOrDefault();
%>
<div class="col-md-8 col-xl-6 chat">
<div class="card">
<div class="card-header msg_head">
<div class="d-flex bd-highlight">
<div class="img_cont">
<img src="../assets/img/1.png" class="rounded-circle user_img">
<span class="online_icon"></span>
</div>
<div class="user_info">
<% if (uu == s_id)
{
%>
<span>Chat with <%=xx2.ToString() %></span>
<%}
else if (uu == r_id)
{ %>
<span>Chat with <%=xx22.ToString() %></span>
<%} %>
<p><%=xxc%></p>
</div>
<div class="video_cam">
<%--<span><i class="fas fa-video"></i></span>
<span><i class="fas fa-phone"></i></span>--%>
</div>
</div>
<%-- <span id="action_menu_btn"><i class="fas fa-ellipsis-v"></i></span>
<div class="action_menu">
<ul>
<li><i class="fas fa-user-circle"></i> View profile</li>
<li><i class="fas fa-users"></i> Add to close friends</li>
<li><i class="fas fa-plus"></i> Add to group</li>
<li><i class="fas fa-ban"></i> Block</li>
</ul>
</div>--%>
</div>
<div class="card-body msg_card_body">
<% var xx3 = (from s in db.messages where s.del == false && ((s.reciever_id == r_id && s.sender_id == s_id) || (s.reciever_id == s_id && s.sender_id == r_id)) select s).OrderBy(a => a.date).ToList();
if (xx3 != null)
{
foreach (var item3 in xx3)
{
DateTime d = DateTime.Parse(item3.date.ToString());
if (item3.reciever_id == r_id && item3.sender_id == s_id)
{
%>
<div class="d-flex justify-content-start mb-4">
<div class="img_cont_msg">
<img src="../assets/img/1.png" class="rounded-circle user_img_msg">
</div>
<div class="msg_cotainer">
<%=item3.message %>
<span class="msg_time"><%=d.ToShortTimeString() %></span>
</div>
</div>
<%
}
else if (item3.reciever_id == s_id && item3.sender_id == r_id)
{ %>
<div class="d-flex justify-content-end mb-4">
<div class="msg_cotainer_send">
<%=item3.message %>
<span class="msg_time_send"><%=d.ToShortTimeString() %></span>
</div>
<div class="img_cont_msg">
<img src="../assets/img/2.png" class="rounded-circle user_img_msg">
</div>
</div>
<%}}}} %>
</div>
<div class="card-footer">
<div class="input-group">
<%--<div class="input-group-append">--%>
<%--<span class="input-group-text attach_btn"><i class="fas fa-paperclip"></i></span>--%>
<%--<asp:FileUpload ID="FileUpload1" class="input-group-text attach_btn" placeholder="upload" runat="server" />--%><%--<i class="fas fa-paperclip"></i>--%>
<%--</div>--%>
<textarea name="" runat="server" id="message" class="form-control type_msg" placeholder="Type your message..."></textarea>
<div class="input-group-append">
<%--<span class="input-group-text send_btn"><i class="fas fa-location-arrow"></i></span>--%>
<asp:Button OnClick="btn_add_Click" CssClass="btn btn-primary" ValidationGroup="b" ID="btn_add" runat="server" Text="send" /><%--<i class="fas fa-location-arrow"></i>--%>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<!--Coded With Love By Mutiullah Samim-->
</form>
<script>
$(document).ready(function () {
$('#action_menu_btn').click(function () {
$('.action_menu').toggle();
});
});
</script>
<script>
function myFunction1() {
var input, filter, div, ul, li, i;
input = document.getElementById("s1");
filter = input.value.toUpperCase();
div = document.getElementById("mytable");
ul = table.getElementsByTagName("ul");
for (i = 0; i < tr.length; i++) {
li = tr[i].getElementsByTagName("li")[1];
if (li) {
if (li.innerHTML.toUpperCase().indexOf(filter) > -1) {
ul[i].style.display = "";
} else {
ul[i].style.display = "none";
}
}
}
}
</script>
</body>
</html>
C＃代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class chat_allchats : System.Web.UI.Page
{
EccoSchoolEntities db = new EccoSchoolEntities();
protected void Page_Load(object sender, EventArgs e)
{
}
//protected void reload_Click(object sender, EventArgs e)
//{
// if (!String.IsNullOrEmpty(Convert.ToString(Request.QueryString["s_id"])) && !String.IsNullOrEmpty(Convert.ToString(Request.QueryString["r_id"])))
// {
// int s_id = int.Parse(Request.QueryString["s_id"].ToString());
// int r_id = int.Parse(Request.QueryString["r_id"].ToString());
// Response.Redirect("allchats.aspx?s_id=" +s_id+"&&r_id="+r_id);
// }
//}
protected void btn_add_Click(object sender, EventArgs e)
{
if (!String.IsNullOrEmpty(Convert.ToString(Request.QueryString["s_id"])) && !String.IsNullOrEmpty(Convert.ToString(Request.QueryString["r_id"])))
{
if (message.Value != "")
{
string n = "", u = "";
if (Session["user_id"] != null && Session["name"] != null)
{
n = Session["name"].ToString();
u = Session["user_id"].ToString();
int uu = int.Parse(u);
int user_id = (from s in db.users where s.id == uu select s.id).FirstOrDefault();
// int yy = Convert.ToInt32(year1.Text);
string user_name = (from s in db.users where s.id == uu select s.name).FirstOrDefault();
DateTime dt = DateTime.Now;
int s_id = int.Parse(Request.QueryString["s_id"].ToString());
int r_id = int.Parse(Request.QueryString["r_id"].ToString());
chat f = db.chat.FirstOrDefault(a => a.del == false && a.sender_id == s_id && a.reciever_id == r_id);
int chat_id, sender_id, reciever_id;
string r_name, s_name;
if (f != null)
{
chat_id = int.Parse(f.id.ToString());
sender_id = int.Parse(f.sender_id.ToString());
reciever_id = int.Parse(f.reciever_id.ToString());
r_name = f.reciever_name.ToString();
s_name = f.sender_name.ToString();
if ( uu ==r_id)
{
messages st2 = new messages
{
sender_id = user_id,
sender_name = user_name,
reciever_id = s_id,
reciever_name = s_name,
date = dt,
chat_id = chat_id,
message = message.Value,
// subject = subj.Text,
del = false
};
db.messages.Add(st2);
db.SaveChanges();
}
else if ( uu == s_id)
{
messages st2 = new messages
{
sender_id = user_id,
sender_name = user_name,
reciever_id = r_id,
reciever_name = r_name,
date = dt,
chat_id = chat_id,
message = message.Value,
// subject = subj.Text,
del = false
};
db.messages.Add(st2);
db.SaveChanges();
}
}
Response.Redirect("allchats.aspx?s_id=" + s_id + "&&r_id=" + r_id);
}
}
}
}
}
that is what i did
如何从数据库自动更新消息框
该做什么？
谢谢
答案 0 :(得分：-1)
如果您只想创建非实时聊天。 我认为有两种方法可以做到这一点。
您可以轻松编写数据库触发器并使用.NET CLR触发器进行捕获 On table update, trigger an action in my .NET code
或者您可以触发重复的Ajax请求并检查表中是否有新消息。
但是我应该说这两种方法都非常老旧。 我猜您在寻找SignalR。