视图模型中的计时器
我在外部程序集中有服务类，我在MEF的视图模型类中注入此类。我需要从视图模型每3-4秒调用一次服务方法。
我从服务新数据获得字典。此词典在视图中绑定到列表框。我需要在视图中使用此数据列表框进行刷新。
在我的解决方案中，我使用DispatcherTimer，但我在calibur.micto中也是MVVM和WPF的绝对优势。在我的案例中，我不知道什么是合适的解决方案。所以，如果有人提前，我将感激不尽。
我的解决方案在这里：
[Export("MainScreen", typeof(IMainViewModel))]
public class MainViewModel : Screen, IMainViewModel
{
[Import]
private Service _service;//import with MEF from external assembly
[Import]
private Connection _conn;//import with MEF from external assembly
//this dictionary is bind to the listbox in view
private MyObservableDictionary<string, User> _users = null;
//temp dictionry
private MyObservableDictionary<string, User> _freshUsers = null;
private int _selectedUserIndex;
private DispatcherTimer _dispatcherTimer;
public Account Account{ get; set;}
public int SelectedUsersIndex
{
get { return _selectedUserIndex; }
set
{
_selectedUserIndex = value;
NotifyOfPropertyChange("SelectedUsersIndex");
}
}
public MainViewModel()
{
_dispatcherTimer = new DispatcherTimer();
_dispatcherTimer.Tick += DispatcherTimer_Tick;
_dispatcherTimer.Interval = TimeSpan.FromSeconds(3);
_dispatcherTimer.Start();
}
//I get every 3-4 sec from server new JSON data and I need update with this data listbox in view
private void DispatcherTimer_Tick(object sender, EventArgs eventArgs)
{
//server ping, call service method
Account.Ping = _service.Ping(Account);
//Refresh data in dictionary
_freshUsers = _service.LoadUsers(Account);
_users.Clear();
SelectedUsersIndex = 1;
foreach (var freshUser in _freshUsers)
{
_users.Add(freshUser);
}
//check if you have new messanges
if (Account.Ping.Rp > 0)
{
//load new messanges
for (int i = 0; i < Account.Ping.Rp; i++)
{
#region load rp
try
{
Rp message = _service.LoadRp(Account);
if (message != null)
{
//show messages
}
}
catch (Exception exception)
{
if (exception.Message == "You haven’t any messanged")
{
}
throw exception;// how handle show this exception in view?
}
#endregion
}
}
}
}
没有找到相关结果
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public MainViewModel() { _stTimer = new System.Threading.Timer(Timer_Tick,null,3000,3000); _dispatcher = Dispatcher.CurrentDispatcher; } private void Timer_Tick(object sender) { Account.Ping = _service.Ping(Account); //Refresh data in dictionary _freshUsers = _service.LoadUsers(Account); _users.Clear(); SelectedUsersIndex = 1; foreach (var freshUser in _freshUsers) { _users.Add(freshUser); } for(int i=0;i<Account.Ping.Rp; i++) { //check if you have new messanges if (Account.Ping.Rp > 0) { Rp message = _service.LoadRp(Account); _messages.Add(message); } } _dispatcher.BeginInvoke((Action)(()=>{OnPropertyChanged("Messages");})); }