private async Task <Activity> HandleSystemMessageAsync(Activity message)
{
TeamEventBase eventData = message.GetConversationUpdateData();
switch (eventData.EventType)
{
case TeamEventType.MembersAdded:
var connector = new ConnectorClient(new Uri(message.ServiceUrl));
connector.SetRetryPolicy(
RetryHelpers.DefaultPolicyBuilder.WaitAndRetryAsync(
new[] { TimeSpan.FromSeconds(2),
TimeSpan.FromSeconds(5),
TimeSpan.FromSeconds(10) })
);
var tenantId = message.GetTenantId();
var botAccount = message.Recipient;
var channelData = message.GetChannelData <TeamsChannelData>();
// if the bot is in the collection of added members,
// then send a welcome to all team members
if (message.MembersAdded.Any(m => m.Id.Equals(botAccount.Id)))
{
// Fetch the members in the current conversation
IList <ChannelAccount> channelAccount =
await connector.Conversations.GetConversationMembersAsync(
message.Conversation.Id);
IEnumerable <TeamsChannelAccount> members =
channelAccount.AsTeamsChannelAccounts();
// send a OneToOne message to each member
foreach (TeamsChannelAccount member in members)
{
await MessageHelpers.SendOneToOneWelcomeMessage(
connector, channelData, botAccount, member, tenantId);
}
}
else
{
// send a OneToOne message to new members
foreach (TeamsChannelAccount member in message.MembersAdded.AsTeamsChannelAccounts())
{
await MessageHelpers.SendOneToOneWelcomeMessage(
connector, channelData, botAccount, member, tenantId);
}
}
break;
case TeamEventType.MembersRemoved:
break;
case TeamEventType.ChannelCreated:
break;
case TeamEventType.ChannelDeleted:
break;
case TeamEventType.ChannelRenamed:
break;
case TeamEventType.TeamRenamed:
break;
default:
break;
}
return(null);
}