一步一步学习SignalR进行实时通信_6_案例

目录

• 一步一步学习SignalR进行实时通信_6_案例1
  • 前言
  • 类的定义
  • 各块功能
    • 后台
    • 前台
  • 结束语
  • 参考文献

一步一步学习SignalR进行实时通信_6_案例1

标签（空格分隔）： SignalR

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前言

由于这段时间在找房子,所以耽误了一段时间。前几讲把一些基础的东西稍微介绍了下,这一讲就简单介绍一个小例子,大致功能是实现在线聊天,并显示在线用户、用户上下线实时提醒。这个例子并不复杂只是把之前介绍联系起来。

在这里为了简单起见,暂时不涉及到数据库的操作。

类的定义

用户信息类UserInfo

public class UserInfo
{
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;summary&gt;</span></span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> ConnectionId</span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;/summary&gt;</span></span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">string</span> ConnectionId { <span class="hljs-keyword">get</span>; <span class="hljs-keyword">set</span>; }
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;summary&gt;</span></span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> 姓名</span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;/summary&gt;</span></span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">string</span> Name { <span class="hljs-keyword">get</span>; <span class="hljs-keyword">set</span>; }
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;summary&gt;</span></span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> 上线时间</span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;/summary&gt;</span></span>
<span class="hljs-keyword">public</span> DateTime ConnectedAt { <span class="hljs-keyword">get</span>; <span class="hljs-keyword">set</span>; }
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;summary&gt;</span></span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> 在线标志</span>
<span class="hljs-comment"><span class="hljs-doctag">///</span> <span class="hljs-doctag">&lt;/summary&gt;</span></span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">bool</span> IsOnline { <span class="hljs-keyword">get</span>; <span class="hljs-keyword">set</span>; }

}

各块功能

后台

上线

public override Task OnConnected()
{
    Interlocked.Increment(ref _usersCount);
    var user = new UserInfo()
    {
        ConnectionId = Context.ConnectionId,
        IsOnline = true,
        Name = "user" + _usersCount,
        ConnectedAt = DateTime.Now
    };
    _users[Context.ConnectionId] = user;
    var notifyAll = (Task)Clients.All.NewUserNotification(user);
    var updateMessage = (Task)Clients.Caller.UpdateMessage(user.Name, _users.Values.ToArray());
    var sendToAll = (Task)Clients.Others.welcome(_users.Values.ToArray());
    return notifyAll.ContinueWith(_ => updateMessage).ContinueWith(_ => sendToAll);
}

下线

public override Task OnDisconnected()
{
    UserInfo user;
    if (_users.TryRemove(Context.ConnectionId, out user))
    {
        return Clients.All.UserDisconnectedNotification(user);
    }
    return base.OnDisconnected();
}

修改昵称

public Task ChangeNickname(string newName)
{
    UserInfo user;
    if (_users.TryGetValue(Context.ConnectionId, out user))
    {
        var oldName = user.Name;
        user.Name = newName;
        return Clients.All.NicknameChangedNotification(user, oldName);
    }
    return null;
}

发送消息给所有人

public Task Send(string message)
{
    UserInfo user;
    if (_users.TryGetValue(Context.ConnectionId, out user))
    {
        var msgToSend = string.Format("[{0}]: {1}", user.Name, message);
        return Clients.All.Message(msgToSend);
    }
    return null;
}

前台

用户上线消息

function newUserNotification(user) {
    if (getUserElement(user.ConnectionId).length == 0) {
        $("#users").append($(getUserListItem(user)));
    }
    systemMessage("欢迎 " + user.Name + " 用户进入聊天室!");
}

昵称改变消息

function nicknameChangedNotification(user, oldName) {
    var userElement = getUserElement(user.ConnectionId);
    if (userElement.length > 0) {
        userElement.replaceWith($(getUserListItem(user)));
        systemMessage(oldName + " 改名为 " + user.Name + ".");
    }
    if (user.Id === $.connection.hub.id) {
        $("#name").text(user.Name);
    }

用户下线消息

function userDisconnectedNotification(user) {
    var userElement = getUserElement(user.ConnectionId);
    if (userElement.length > 0) {
        systemMessage(user.Name + " 离开聊天室.");
        userElement.remove();
    }
}

更新个人信息

function updateMessage(assignedNickname, userList) {
    var result = "";
    for (var i = 0; i < userList.length; i++) {
        var user = userList[i];
        result += getUserListItem(user);
    }
    $("#users").empty();
    $("#users").append(result);
    $("#username").text(assignedNickname);
    $("#user-info").show();
}

用户上线提醒

function welcome(userList) {
    var result = "";
    for (var i = 0; i < userList.length; i++) {
        var user = userList[i];
        result += getUserListItem(user);
    }
    $("#users").empty();
    $("#users").append(result);
}

发送消息

function message(message) {
var $panel = $("#chatpanel");
$panel.append("<li class='list-group-item'>" + message + "</li>");
$panel.scrollTop($panel[0].scrollHeight);
}

效果图

结束语

功能较为简单,本来还加了其他的功能,但是由于最近太忙了,打好了一半然后又全部删掉了,后面有时间再慢慢加上去。

源码下载

本文发布至作业部落

参考文献

SignalR Programming in Microsoft ASP.NET pdf 下载