Add ClientManager usage to management sample

SignalR client output sample:

```
User 'User' with connection id 'CKZhiNk__nyv3Vrz8SnK_Q1448c44c1' connected.
User: gets message from service: 'aaa'
```
MessagePublisher output sample:
```
*********Usage*********
send user <User Id> <Message>
send users <User Id List (Seperated by ',')> <Message>
send group <Group Name> <Message>
send groups <Group List (Seperated by ',')> <Message>
usergroup add <User Id> <Group Name>
usergroup remove <User Id> <Group Name>
broadcast <Message>
close <Connection ID> <Reason>
checkexist connection <Connection ID>
checkexist user <User ID>
checkexist group <Group Name>
***********************
> checkexist connection CKZhiNk__nyv3Vrz8SnK_Q1448c44c1
connection 'CKZhiNk__nyv3Vrz8SnK_Q1448c44c1' exists.
> checkexist connection CKZhiNk__nyv3Vrz8SnK_Q1448c44c2
connection 'CKZhiNk__nyv3Vrz8SnK_Q1448c44c2' does not exist.
> checkexist user User
user 'User' exists.
> send user User abc
send message 'abc' to 'User'
```

Author: Y-Sindo

samples/Management/MessagePublisher/MessagePublisher.cs

@@ -75,6 +75,22 @@ public Task SendMessages(string command, string receiver, string message)
             }
         }
 
+        public Task CloseConnection(string connectionId, string reason)
+        {
+            return _hubContext.ClientManager.CloseConnectionAsync(connectionId, reason);
+        }
+
+        public Task<bool> CheckExist(string type, string id)
+        {
+            return type switch
+            {
+                "connection" => _hubContext.ClientManager.ConnectionExistsAsync(id),
+                "user" => _hubContext.ClientManager.UserExistsAsync(id),
+                "group" => _hubContext.ClientManager.UserExistsAsync(id),
+                _ => throw new NotSupportedException(),
+            };
+        }
+
         public Task DisposeAsync() => _hubContext?.DisposeAsync();
     }
 }

samples/Management/MessagePublisher/Program.cs

@@ -10,12 +10,14 @@
 
 namespace Microsoft.Azure.SignalR.Samples.Management
 {
-    class Program
+    public class Program
     {
-        static void Main(string[] args)
+        public static void Main(string[] args)
         {
-            var app = new CommandLineApplication();
-            app.FullName = "Azure SignalR Management Sample: Message Publisher";
+            var app = new CommandLineApplication
+            {
+                FullName = "Azure SignalR Management Sample: Message Publisher"
+            };
             app.HelpOption("--help");
             app.Description = "Message publisher using Azure SignalR Service Management SDK.";
 
@@ -28,7 +30,7 @@ static void Main(string[] args)
                 .Build();
 
 
-            app.OnExecute(async() =>
+            app.OnExecute(async () =>
             {
                 var connectionString = connectionStringOption.Value() ?? configuration["Azure:SignalR:ConnectionString"];
 
@@ -82,8 +84,8 @@ private static async Task StartAsync(MessagePublisher publisher)
 
                     if (args.Length == 2 && args[0].Equals("broadcast"))
                     {
-                        Console.WriteLine($"broadcast message '{args[1]}'");
                         await publisher.SendMessages(args[0], null, args[1]);
+                        Console.WriteLine($"broadcast message '{args[1]}'");
                     }
                     else if (args.Length == 4 && args[0].Equals("send"))
                     {
@@ -96,10 +98,21 @@ private static async Task StartAsync(MessagePublisher publisher)
                         var preposition = args[1] == "add" ? "to" : "from";
                         Console.WriteLine($"{args[1]} user '{args[2]}' {preposition} group '{args[3]}'");
                     }
+                    else if (args.Length == 3 && args[0] == "close")
+                    {
+                        await publisher.CloseConnection(args[1], args[2]);
+                        Console.WriteLine($"Close connection '{args[1]}' because '{args[2]}'");
+                    }
+                    else if (args.Length == 3 && args[0] == "checkexist")
+                    {
+                        var exist = await publisher.CheckExist(args[1].ToLowerInvariant(), args[2]);
+                        Console.WriteLine(exist ? $"{args[1]} '{args[2]}' exists." : $"{args[1]} '{args[2]}' does not exist.");
+                    }
                     else
                     {
                         Console.WriteLine($"Can't recognize command {argLine}");
                     }
+                    Console.Write("> ");
                 }
             }
             finally
@@ -110,16 +123,21 @@ private static async Task StartAsync(MessagePublisher publisher)
 
         private static void ShowHelp()
         {
-            Console.WriteLine(
-                "*********Usage*********\n" +
-                "send user <User Id> <Message>\n" +
-                "send users <User Id List (Seperated by ',')> <Message>\n" +
-                "send group <Group Name> <Message>\n" +
-                "send groups <Group List (Seperated by ',')> <Message>\n" +
-                "usergroup add <User Id> <Group Name>\n" +
-                "usergroup remove <User Id> <Group Name>\n" +
-                "broadcast <Message>\n" +
-                "***********************");
+            Console.Write(
+@"*********Usage*********
+send user <User Id> <Message>
+send users <User Id List (Seperated by ',')> <Message>
+send group <Group Name> <Message>
+send groups <Group List (Seperated by ',')> <Message>
+usergroup add <User Id> <Group Name>
+usergroup remove <User Id> <Group Name>
+broadcast <Message>
+close <Connection ID> <Reason>
+checkexist connection <Connection ID>
+checkexist user <User ID>
+checkexist group <Group Name>
+***********************
+> ");
         }
 
         private static void MissOptions()

samples/Management/SignalRClient/Program.cs

@@ -15,7 +15,7 @@ class Program
     {
         private const string MessageHubEndpoint = "http://localhost:5000/Message";
         private const string Target = "Target";
-        private const string DefaultUser = "User";
+        private const string DefaultUser = "TestUser";
 
         static void Main(string[] args)
         {
@@ -37,7 +37,10 @@ static void Main(string[] args)
                 await Task.WhenAll(from conn in connections
                                    select conn.StartAsync());
 
-                Console.WriteLine($"{connections.Count} Client(s) started...");
+                foreach (var (connection, userId) in connections.Zip(userIds))
+                {
+                    Console.WriteLine($"User '{userId}' with connection id '{connection.ConnectionId}' connected.");
+                }
                 Console.ReadLine();
 
                 await Task.WhenAll(from conn in connections