WTelegramClient/EXAMPLES.md

Example programs using WTelegramClient

The following codes can be saved into a Program.cs file with the only addition of some using on top of file, like

using System;
using System.Linq;
using TL;

Those examples use environment variables for configuration so make sure to go to your Project Properties > Debug > Environment variables and add at least these variables with adequate value: api_id, api_hash, phone_number

Remember that these are just simple example codes that you should adjust to your needs. In real production code, you're supposed to properly test the success of each operation.

Send a message to someone by @username

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var resolved = await client.Contacts_ResolveUsername("username");
await client.SendMessageAsync(resolved, "Hello!");

Note: This also works if the @username points to a chat, but you must join the chat before posting there. You can check resolved properties to ensure it's a user or a chat. If the username is invalid/unused, the API call raises an exception.

Send a message to someone by phone number

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var contacts = await client.Contacts_ImportContacts(new[] { new InputPhoneContact { phone = "+PHONENUMBER" } });
if (contacts.imported.Length > 0)
    await client.SendMessageAsync(contacts.users[contacts.imported[0].user_id], "Hello!");

Note: To prevent spam, Telegram may restrict your ability to add new phone numbers.

List all chats (groups/channels) the user is in and send a message to one

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
foreach (var (id, chat) in chats.chats)
    if (chat.IsActive)
        Console.WriteLine($"{id} : {chat}");
Console.Write("Choose a chat ID to send a message to: ");
long chatId = long.Parse(Console.ReadLine());
await client.SendMessageAsync(chats.chats[chatId], "Hello, World");

Note: the list returned by Messages_GetAllChats contains the access_hash for those chats.
See a longer version of this example in Examples/Program_GetAllChats.cs

Schedule a message to be sent to a chat

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
InputPeer peer = chats.chats[1234567890]; // the chat we want
DateTime when = DateTime.UtcNow.AddMinutes(3);
await client.SendMessageAsync(peer, "This will be posted in 3 minutes", schedule_date: when);

Upload a media file and post it with caption to a chat

const int TargetChatId = 1234567890; // the chat we want
const string Filepath = @"C:\...\photo.jpg";

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
InputPeer peer = chats.chats[TargetChatId];
var inputFile = await client.UploadFileAsync(Filepath);
await client.SendMediaAsync(peer, "Here is the photo", inputFile);

List all dialogs (chats/groups/channels/user chat) the user is in

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var dialogsBase = await client.Messages_GetDialogs(default, 0, null, 0, 0);
if (dialogsBase is Messages_Dialogs dialogs)
    while (dialogs.dialogs.Length != 0)
    {
        foreach (var dialog in dialogs.dialogs)
            switch (dialogs.UserOrChat(dialog))
            {
                case UserBase user when user.IsActive: Console.WriteLine("User " + user); break;
                case ChatBase chat when chat.IsActive: Console.WriteLine(chat); break;
            }
        var lastDialog = dialogs.dialogs[^1];
        var lastMsg = dialogs.messages.LastOrDefault(m => m.Peer.ID == lastDialog.Peer.ID && m.ID == lastDialog.TopMessage);
        var offsetPeer = dialogs.UserOrChat(lastDialog).ToInputPeer();
        dialogs = (Messages_Dialogs)await client.Messages_GetDialogs(lastMsg?.Date ?? default, lastDialog.TopMessage, offsetPeer, 500, 0);
    }

Note: the lists returned by Messages_GetDialogs contains the access_hash for those chats and users.
See also the Main method in Examples/Program_ListenUpdates.cs.

Get all members from a chat

For a simple Chat: (see Terminology in ReadMe)

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chatFull = await client.Messages_GetFullChat(1234567890); // the chat we want
foreach (var (id, user) in chatFull.users)
    Console.WriteLine(user);

For a Channel/Group:

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
var channel = (Channel)chats.chats[1234567890]; // the channel we want
for (int offset = 0; ;)
{
    var participants = await client.Channels_GetParticipants(channel, null, offset, 1000, 0);
    foreach (var (id, user) in participants.users)
        Console.WriteLine(user);
    offset += participants.participants.Length;
    if (offset >= participants.count) break;
}

Get all messages (history) from a chat

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
InputPeer peer = chats.chats[1234567890]; // the chat we want
for (int offset = 0; ;)
{
    var messagesBase = await client.Messages_GetHistory(peer, 0, default, offset, 1000, 0, 0, 0);
    if (messagesBase is not Messages_ChannelMessages channelMessages) break;
    foreach (var msgBase in channelMessages.messages)
        if (msgBase is Message msg)
        {
            // process the message
        }
    offset += channelMessages.messages.Length;
    if (offset >= channelMessages.count) break;
}

Monitor all Telegram events happening for the user

This is done through the client.Update callback event. See Examples/Program_ListenUpdates.cs.

Monitor new messages being posted in chats

You have to catch Update events containing an UpdateNewMessage.

See the DisplayMessage method in Examples/Program_ListenUpdates.cs.

You can filter specific chats the message are posted in, by looking at the Message.peer_id field.

Download media files you save/forward to yourself

See Examples/Program_DownloadSavedMedia.cs.

Collect Access Hash and save them for later use

You can automate the collection of access_hash for the various resources obtained in response to API calls or Update events, so that you don't have to remember them by yourself or ask the API about them each time.

This is done by activating the experimental client.CollectAccessHash system. See Examples/Program_CollectAccessHash.cs for how to enable it, and save/restore them for later use.

Use a proxy to connect to Telegram

This can be done using the client.TcpHandler delegate and a proxy library like StarkSoftProxy:

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
client.TcpHandler = async (address, port) =>
{
    var proxy = new Socks5ProxyClient(ProxyHost, ProxyPort, ProxyUsername, ProxyPassword);
    return proxy.CreateConnection(address, port);
};
var user = await client.LoginUserIfNeeded();
Console.WriteLine($"We are logged-in as {user.username ?? user.first_name + " " + user.last_name}");