SignalR 2.0 Hub 公共方法无法通过 Javascript 访问

Question

我正在尝试使用 SignalR 集线器中的以下服务器代码获取已连接用户的列表。对于存储内存数据，我使用以下类：

public class UserInfo
    {
        public string ConnectionId { get; set; }
        public string UserName { get; set; }
        public string Role { get; set; }
    }

当用户连接时，我将用户添加到连接用户列表中：

public override Task OnConnected()
            {
                if (Context.User.Identity.IsAuthenticated)
                {
                    if (Context.User.IsInRole("User"))
                    {
                        ui.Add(new UserInfo { ConnectionId = Context.ConnectionId, UserName = Context.User.Identity.Name, Role = "User" });
                    }
                    else
                    {
                        ui.Add(new UserInfo { ConnectionId = Context.ConnectionId, UserName = Context.User.Identity.Name, Role = "Operator" });
                    }
                }
                return base.OnConnected();
            }

这是我获取当前连接用户列表的方式：

public IEnumerable<UserInfo> GetUsers()
        {
            var x = (from a in ui where a.Role == "User" select new UserInfo { UserName = a.UserName, ConnectionId = a.ConnectionId }).ToList();
            return x;
        }
        public IEnumerable<UserInfo> GetOperators()
        {
            var y = (from a in ui where a.Role == "Operator" select new UserInfo { UserName = a.UserName, ConnectionId = a.ConnectionId }).ToList();
            return y;
        }

不幸的是，公共方法 GetOperators/GetUsers 无法访问，我没有在客户端收到数据：

$(function () {
            // Declare a proxy to reference the hub. 
            var chat = $.connection.chatHub;
            //Here I'm calling hub public methods
            chat.getOperators = function (data) {
                alert(data);
            };
            chat.getUsers = function (data) {
                alert(data);
            };
            // Create a function that the hub can call to broadcast messages.
            chat.client.addChatMessage = function (name, message) {
                // Html encode display name and message. 
                var encodedName = $('<div />').text(name).html();
                var encodedMsg = $('<div />').text(message).html();
                // Add the message to the page. 
                $('#discussion').append('<li><strong>' + encodedName
                    + '</strong>:&nbsp;&nbsp;' + encodedMsg + '</li>');
            };
            // Get the user name and store it to prepend to messages.
            $('#displayname').val(prompt('Enter your name:', ''));
            // Set initial focus to message input box.  
            $('#message').focus();
            // Start the connection.
            $.connection.hub.start().done(function () {
                $('#sendmessage').click(function () {
                    // Call the Send method on the hub. 
                    chat.server.sendChatMessage($('#displayname').val(),      $('#message').val());             
                    // Clear text box and reset focus for next comment. 
                    $('#message').val('').focus();
                });
            });
        });

Answer 1

您调用服务器的语法错误；这里：

chat.getUsers = function (data) {
    alert(data);
};

将简单地将chat.getUsers 定义为一个函数。

你可能想要

chat.server.getUsers().done(function(data) {
    console.log(data);
}).fail(function(error) {
    console.log("failed to get data", error);
});

再看看documentation。

Answer 2

你可以试试这个

 //on your client action do a server call 

 chat.server.getOperators();

和

//on your client action do a server call  
 chat.server.getUsers(); 

而不是

chat.getOperators = function (data) {
                alert(data);
            };
            chat.getUsers = function (data) {
                alert(data);
            };