/// <summary>
/// 模拟消息
/// </summary>
/// <returns></returns>
public async Task FakeMessaging()
{
//var shouldReply = new Random().Next(0, 3) > 0 ? true : false;
var shouldReply = true;
if (shouldReply)
{
ScrollToMessage(Messages.Last().Last());
IsTyping = true;
await Task.Delay(TimeSpan.FromSeconds(3));
var message = new Message
{
Content = "你好，欢迎使用DCMS帮助服务，请问你有什么需要解答的吗？",
CreationDate = DateTime.Now,
Sender = CurrentConversation.Peer,
ISentPreviousMessage = Messages.Last().Last().ISent,
ISent = false,
ConversationId = CurrentConversation.Id,
SenderId = CurrentConversation.Peer.Id
};
Messages.Last().Add(message);
CurrentConversation.LastMessage = message;
await _conversationsDataStore.UpdateItemAsync(CurrentConversation);
IsTyping = false;
ScrollToMessage(message);
await _messagesDataStore.AddItemAsync(message);
}
}
public MessagerPageViewModel(INavigationService navigationService,
IConversationsDataStore conversationsDataStore,
IMessagesDataStore messagesDataStore,
IDialogService dialogService
) : base(navigationService, dialogService)
{
Title = "帮助中心";
_conversationsDataStore = conversationsDataStore;
_messagesDataStore = messagesDataStore;
_messages = new List <Message>();
//回复
this.ReplyMessageSelectedCommand = ReactiveCommand.Create <Message>((message) =>
{
ScrollToMessage(message);
});
this.MessageSwippedCommand = ReactiveCommand.Create <Message>((message) =>
{
ReplyMessage = message;
MessagingCenter.Send(this, Constants.ShowKeyboard, new MyFocusEventArgs {
IsFocused = true
});
});
//发送消息
this.SendMessageCommand = ReactiveCommand.CreateFromTask(async() =>
{
var message = new Message
{
Content = CurrentMessage,
ReplyTo = ReplyMessage,
CreationDate = DateTime.Now,
Sender = new User(),
ISentPreviousMessage = (bool)Messages?.Last()?.Last()?.ISent,
ISent = true,
ConversationId = CurrentConversation.Id,
SenderId = new User().Id
};
CurrentConversation.LastMessage = message;
await _conversationsDataStore.UpdateItemAsync(CurrentConversation);
CurrentMessage = string.Empty;
Messages.Last().Add(message);
ReplyMessage = null;
await _messagesDataStore.AddItemAsync(message);
CurrentConversation.LastMessage = message;
ScrollToMessage(message);
await FakeMessaging();
}, this.WhenAnyValue(vm => vm.CurrentMessage, curm => !String.IsNullOrEmpty(curm)));
//取消回复
this.CancelReplyCommand = ReactiveCommand.Create(() =>
{
ReplyMessage = null;
MessagingCenter.Send(this, Constants.ShowKeyboard, new MyFocusEventArgs {
IsFocused = false
});
});
//初始化
this.Load = ReactiveCommand.CreateFromTask(() => Task.Run(async() =>
{
//获取对话
this.CurrentConversation = await _conversationsDataStore.GetItemAsync(this.ConversationId);
//获取消息
var messages = await _messagesDataStore.GetMessagesForConversation(this.ConversationId);
_messages.AddRange(messages);
var messagesGroups = _messages.GroupBy(m => m.CreationDate.Day)
.Select(grp =>
{
var messagesGrp = grp.ToList().OrderBy(m => m.CreationDate);
var msg = messagesGrp.First();
var date = msg.CreationDate.Date;
var dayDiff = DateTime.Now.Day - date.Day;
string groupHeader = string.Empty;
if (dayDiff == 0)
{
groupHeader = TextResources.Today;
}
else if (dayDiff == 1)
{
groupHeader = TextResources.Yesterday;
}
else
{
groupHeader = date.ToString("MM-dd-yyyy");
}
return(new MessagesGroup
(
dateTime: date,
groupHeader: groupHeader,
messages: new ObservableCollection <Message>(messagesGrp)
));
})
.OrderBy(m => m.DateTime.Day)
.ToList();
this.Messages = new ObservableCollection <MessagesGroup>(messagesGroups);
await Task.Delay(TimeSpan.FromSeconds(0.5));
if (Messages.Any())
{
ScrollToMessage(Messages?.Last()?.Last());
}
}));
this.BindBusyCommand(Load);
}
