public static void StartReceiving(
this ITelegramBotClient botClient,
IUpdateHandler updateHandler,
ReceiverOptions?receiverOptions = default,
CancellationToken cancellationToken = default)
{
if (botClient is null)
{
throw new ArgumentNullException(nameof(botClient));
}
if (updateHandler is null)
{
throw new ArgumentNullException(nameof(updateHandler));
}
// ReSharper disable once MethodSupportsCancellation
Task.Run(async() =>
{
try
{
await ReceiveAsync(
botClient: botClient,
updateHandler: updateHandler,
receiverOptions: receiverOptions,
cancellationToken: cancellationToken
);
}
catch (OperationCanceledException)
{
// ignored
}
catch (Exception ex)
{
try
{
await updateHandler.HandleErrorAsync(
botClient: botClient,
exception: ex,
cancellationToken: cancellationToken
);
}
catch (OperationCanceledException)
{
// ignored
}
}
});
}
/// <inheritdoc />
public async Task ReceiveAsync(
IUpdateHandler updateHandler,
CancellationToken cancellationToken = default)
{
if (updateHandler is null)
{
throw new ArgumentNullException(nameof(updateHandler));
}
var allowedUpdates = _receiverOptions?.AllowedUpdates;
var limit = _receiverOptions?.Limit ?? default;
var messageOffset = _receiverOptions?.Offset ?? 0;
var emptyUpdates = EmptyUpdates;
if (_receiverOptions?.ThrowPendingUpdates is true)
{
try
{
messageOffset = await _botClient.ThrowOutPendingUpdatesAsync(
cancellationToken : cancellationToken
);
}
catch (OperationCanceledException)
{
// ignored
}
}
while (!cancellationToken.IsCancellationRequested)
{
var timeout = (int)_botClient.Timeout.TotalSeconds;
var updates = emptyUpdates;
try
{
var request = new GetUpdatesRequest
{
Limit = limit,
Offset = messageOffset,
Timeout = timeout,
AllowedUpdates = allowedUpdates,
};
updates = await _botClient.MakeRequestAsync(
request : request,
cancellationToken :
cancellationToken
).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
// Ignore
}
catch (Exception exception)
{
try
{
await updateHandler.HandleErrorAsync(
botClient : _botClient,
exception : exception,
cancellationToken : cancellationToken
).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
// ignored
}
}
foreach (var update in updates)
{
try
{
await updateHandler.HandleUpdateAsync(
botClient : _botClient,
update : update,
cancellationToken : cancellationToken
).ConfigureAwait(false);
messageOffset = update.Id + 1;
}
catch (OperationCanceledException)
{
// ignored
}
}
}
}