Wie Timer zum Binden hinzufügen wpf uwp C#

Question

Wie füge ich einen Timer für alle verbindlichen Objekte hinzu? Ich habe eine Liste von Bikes, die zwei propertys enthält (I erhalten propertys von JSON):

using myApi; 

    public sealed partial class BikesSample: Page 
    { 
    List<Bike> Bikes = new List<Bike>(); 

    public BikesSample() 
    { 
     this.InitializeComponent(); 
     //get JSON 
     dynamic getList = myApi.Api.getList(); 
     Newtonsoft.Json.Linq.JArray y = getList.list; 

     for (int x = 0; x < y.Count; x++) 
     { 
     //converting time 
     double doubleTime =  Convert.ToDouble((getList.list[x].endtime).ToString()); 
     TimeSpan ResTime = TimeSpan.FromSeconds(doubleTime); 

     Bikes.Add(new Bike() 
        { number = (getList.list[x].number).ToString(), 
         endtime = ResTime.ToString()}); 

        BikesList.ItemsSource = Bikes; 
     } 
    } 
} 
public class reserveBike 
{ 
    public string number { get; set; } 
    public string endtime { get; set; } 
} 

Und XAML wie:

<ListView x:Name="BikesList" Margin="0,60,-360,-630"> 
      <ListView.ItemTemplate> 
       <DataTemplate> 
        <Grid Width="360" VerticalAlignment="Center"> 
         <Grid.ColumnDefinitions> 
          <ColumnDefinition/> 
          <ColumnDefinition/> 
         </Grid.ColumnDefinitions> 

         <TextBlock Grid.Column="0" Text="{Binding number}"/> 

         <TextBlock Grid.Column="1" Text="{Binding endtime}"/> //Here should be a timer mm:ss 

        </Grid> 
       </DataTemplate> 
      </ListView.ItemTemplate> 
     </ListView> 

Ich brauche alle "endtime" propertys bei Listview als Timer zu machen . Ich habe versucht, DispatcherTimer zu verwenden, aber ich verstehe nicht, wo und wie ich DispatcherTimer.Tick-Methode verwenden sollte. Endzeit-Eigenschaft bekomme ich in Sekunden.

Answer 1

Ich habe MVVM Konzept verwendet. Implementieren Sie INotifyPropertyChanged für Bike, da es ui für jede Sekunde aktualisiert werden muss;

public class Bike:INotifyPropertyChanged 
     { 
      public string number { get; set; } 
      public string endtime { get; set; } 
      string _foramtedtime; 
      public string FormattedEndTime 
      { 
       get 
       { 
        return _foramtedtime; 
       } 
       set 
       { 

        if(value!=_foramtedtime) 
        { 
         _foramtedtime = value; 
         OnPropertyChanged("FormattedEndTime"); 
        } 
       } 
       } 

      void OnPropertyChanged(string propertyName) 
      { 
       // the new Null-conditional Operators are thread-safe: 
       this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
      } 


      public TimeSpan EndTimeinTimeSpan; 

      public event PropertyChangedEventHandler PropertyChanged; 

      public Bike(string numb,string endtim) 
      { 
       number = numb; 
       endtime = endtim; 
       var seconds = int.Parse(endtime); 
       FormattedEndTime= string.Format("{0:00}:{1:00}",(seconds/60) % 60, seconds % 60); 
       EndTimeinTimeSpan = TimeSpan.Parse(string.Format("{0:00}:{1:00}:{2:00}", seconds/3600, (seconds/60) % 60, seconds % 60)); 
      } 
     } 
    public sealed partial class MainPage : Page 
     { 
       VM = new TestViewModel(); 
      DataContext = VM; 
      this.Loaded += MainPage_Loaded; 
       DispatcherTimer timertostoop; 
       DispatcherTimer timer; 
       public MainPage() 
       { 
         TimeSpan time =(DataContext as TestViewModel).Bikes.Max(x => x.EndTimeinTimeSpan); 
       timertostoop = new DispatcherTimer() { Interval = time }; 
       timertostoop.Tick += Timertostoop_Tick; 
       timer = new DispatcherTimer() { Interval =TimeSpan.FromSeconds(1) }; 
       timer.Tick += Timer_Tick; 
       } 
       private void Timertostoop_Tick(object sender, object e) 
      { 
       if (timer != null && timer.IsEnabled) 
        timer.Stop(); 
       timertostoop.Stop(); 
      } 

      private async void MainPage_Loaded(object sender, RoutedEventArgs e) 
      { 

       timer.Start(); 

      } 
      private void Timer_Tick(object sender, object e) 
      { 
     if(!timertostoop.IsEnabled) 
      timertostoop.Start(); 
       foreach(var bike in VM.Bikes) 
       { 
        if(bike.EndTimeinTimeSpan>TimeSpan.FromSeconds(0)) 
        { 
         bike.EndTimeinTimeSpan = bike.EndTimeinTimeSpan - TimeSpan.FromSeconds(1); 
         bike.FormattedEndTime = string.Format("{0:00}:{1:00}", Math.Floor((bike.EndTimeinTimeSpan.TotalSeconds/ 60)), bike.EndTimeinTimeSpan.Seconds); 
        } 
       } 
      } 

     } 
    <ListView x:Name="BikesList" ItemsSource="{Binding Bikes}"> 
      <ListView.ItemTemplate> 
       <DataTemplate> 
        <Grid Width="360" VerticalAlignment="Center"> 
         <Grid.ColumnDefinitions> 
          <ColumnDefinition/> 
          <ColumnDefinition/> 
         </Grid.ColumnDefinitions> 

         <TextBlock Grid.Column="0" Text="{Binding number}"/> 

         <TextBlock Grid.Column="1" Text="{Binding FormattedEndTime}"/> 

        </Grid> 
       </DataTemplate> 
      </ListView.ItemTemplate> 
     </ListView>