Throw exception if calling API without connecting first.

EXAMPLES.md

@@ -345,7 +345,7 @@ See [Examples/Program_CollectAccessHash.cs](Examples/Program_CollectAccessHash.c
 
 <a name="proxy"></a>
 ### Use a proxy to connect to Telegram
-SOCKS/HTTP proxies can be used through the `client.TcpHandler` delegate and a proxy library like [StarkSoftProxy](https://www.nuget.org/packages/StarkSoftProxy/):
+SOCKS/HTTPS proxies can be used through the `client.TcpHandler` delegate and a proxy library like [StarkSoftProxy](https://www.nuget.org/packages/StarkSoftProxy/):
 ```csharp
 using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
 client.TcpHandler = async (address, port) =>

Examples/Program_ListenUpdates.cs

@@ -32,16 +32,16 @@ namespace WTelegramClientTest
 			}
 		}
 
-		// in this example, we're not using async/await, so we just return Task.CompletedTask
+		// if not using async/await, we could just return Task.CompletedTask
-		private static Task Client_OnUpdate(IObject arg)
+		private static async Task Client_OnUpdate(IObject arg)
 		{
-			if (arg is not UpdatesBase updates) return Task.CompletedTask;
+			if (arg is not UpdatesBase updates) return;
 			updates.CollectUsersChats(Users, Chats);
 			foreach (var update in updates.UpdateList)
 				switch (update)
 				{
-					case UpdateNewMessage unm: DisplayMessage(unm.message); break;
+					case UpdateNewMessage unm: await DisplayMessage(unm.message); break;
-					case UpdateEditMessage uem: DisplayMessage(uem.message, true); break;
+					case UpdateEditMessage uem: await DisplayMessage(uem.message, true); break;
 					case UpdateDeleteChannelMessages udcm: Console.WriteLine($"{udcm.messages.Length} message(s) deleted in {Chat(udcm.channel_id)}"); break;
 					case UpdateDeleteMessages udm: Console.WriteLine($"{udm.messages.Length} message(s) deleted"); break;
 					case UpdateUserTyping uut: Console.WriteLine($"{User(uut.user_id)} is {uut.action}"); break;
@@ -53,10 +53,10 @@ namespace WTelegramClientTest
 					case UpdateUserPhoto uup: Console.WriteLine($"{User(uup.user_id)} has changed profile photo"); break;
 					default: Console.WriteLine(update.GetType().Name); break; // there are much more update types than the above cases
 				}
-			return Task.CompletedTask;
 		}
 
-		private static void DisplayMessage(MessageBase messageBase, bool edit = false)
+		// in this example method, we're not using async/await, so we just return Task.CompletedTask
+		private static Task DisplayMessage(MessageBase messageBase, bool edit = false)
 		{
 			if (edit) Console.Write("(Edit): ");
 			switch (messageBase)
@@ -64,6 +64,7 @@ namespace WTelegramClientTest
 				case Message m: Console.WriteLine($"{Peer(m.from_id) ?? m.post_author} in {Peer(m.peer_id)}> {m.message}"); break;
 				case MessageService ms: Console.WriteLine($"{Peer(ms.from_id)} in {Peer(ms.peer_id)} [{ms.action.GetType().Name[13..]}]"); break;
 			}
+			return Task.CompletedTask;
 		}
 
 		private static string User(long id) => Users.TryGetValue(id, out var user) ? user.ToString() : $"User {id}";

FAQ.md

@@ -177,7 +177,7 @@ To help determine if `chats.chats` is empty or does not contain a certain chat,
 or simply use a debugger: Place a breakpoint after the Messages_GetAllChats call, run the program up to there, and use a Watch pane to display the content of the chats.chats dictionary.
 
 <a name="shutdown"></a>
-#### 10. I get "Connection shut down" errors in my logs
+#### 11. I get "Connection shut down" errors in my logs
 
 There are various reasons why you may get this error. Here are the explanation and how to solve it:
 
@@ -200,7 +200,7 @@ you might also get Connection shutdown because your client couldn't send Pings t
 In this case, you can use the `PingInterval` property to increase the delay between pings *(for example 300 seconds instead of 60)*.
 
 <a name="TLSharp"></a>
-#### 11. How to migrate from TLSharp? How to sign-in/sign-up/register account properly?
+#### 12. How to migrate from TLSharp? How to sign-in/sign-up/register account properly?
 
 First, make sure you read the [ReadMe documentation](README.md) completely, it contains essential information and a quick tutorial to easily understand how to correctly use the library.
 
@@ -226,7 +226,7 @@ In particular, it will detect and handle automatically and properly the various
 Contrary to TLSharp, WTelegramClient supports MTProto v2.0 (more secured), transport obfuscation, protocol security checks, MTProto Proxy, real-time updates, multiple DC connections, API documentation in Intellisense...
 
 <a name="heroku"></a><a name="vps"></a><a name="host"></a>
-#### 12. How to host my userbot online?
+#### 13. How to host my userbot online?
 
 If you need your userbot to run 24/7, you would typically design your userbot as a Console program, compiled for Linux or Windows,
 and hosted online on any [VPS Hosting](https://www.google.com/search?q=vps+hosting) (Virtual Private Server).  

src/Client.cs

@@ -1046,6 +1046,7 @@ namespace WTelegram
 
 		private async Task SendAsync(IObject msg, bool isContent, Rpc rpc = null)
 		{
+			if (_reactorTask == null) throw new ApplicationException("You must connect to Telegram first");
 			isContent &= _dcSession.AuthKeyID != 0;
 			(long msgId, int seqno) = NewMsgId(isContent);
 			if (rpc != null)