トリガを使用してXAML Mapのプッシュピンの背景色を変更します。

Question

DataTemplateトリガを使用してXAMLマップのプッシュピンの背景色を変更しようとしていますが、そのアイデアは、地図のItemSourceがPushpinModelのObservableCollectionにバインドされ、プロパティIsOnlineの値がtrueのときには、押ボタンが緑色になります。私は変更しないでいると思う原因私は、SetterのPropertyに関するいくつかの疑問を持っている

namespace MyNamespace 
{ 
    internal class Pushpins : ObservableCollection<PushpinModel> { } 

    internal class PushpinModel 
    { 
     public PushpinModel(double latitude, double longitude) 
     { 
      Location = new Location(latitude, longitude); 
     } 
     public Location Location { get; set; } 
     public bool IsOnline { get; set; } = false; 
    } 

    internal class GeolocationViewModel : INotifyPropertyChanged 
    { 
     public GeolocationViewModel() 
     { 
      pushpinCollection = new Pushpins(); 
      CreatePushpins(); 
     } 

     private Pushpins pushpinCollection; 
     public Pushpins PushpinCollection 
     { 
      get { return pushpinCollection; } 
     } 

     private void CreatePushpins() 
     { 
      Random rnd = new Random(); 

      for (int i = 1; i <= 100; i++) 
      { 
       PushpinModel pin = new PushpinModel(rnd.NextDouble() * 180 - 90, rnd.NextDouble() * 360 - 180); 

       if (rnd.NextDouble() >= 0.5) 
        pin.IsOnline = true; 

       pushpinCollection.Add(pin); 
      } 
      OnPropertyChanged("PushpinCollection"); 
     } 

     #region IPropertyChange 
     public event PropertyChangedEventHandler PropertyChanged; 

     protected void OnPropertyChanged(string propertyName) 
     { 
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
     } 
     #endregion 
    } 
} 

：

<m:Map CredentialsProvider="XXX" Mode="Road"> 
    <m:MapItemsControl Name="Pushpins" ItemsSource="{Binding PushpinCollection}" > 
     <m:MapItemsControl.ItemTemplate> 
      <DataTemplate> 
       <m:Pushpin Location="{Binding Path=Location}" /> 
       <DataTemplate.Triggers> 
        <DataTrigger Binding="{Binding Path=IsOnline}" Value="True"> 
         <Setter Property="m:Pushpin.Background" Value="Green"></Setter> 
        </DataTrigger> 
       </DataTemplate.Triggers> 
      </DataTemplate> 
     </m:MapItemsControl.ItemTemplate> 
    </m:MapItemsControl> 
</m:Map> 

、ここでは、ビューモデルGeolocationViewModel.csである：ここでは

は私Geolocation.xamlです右の項目。

提案がありますか？君たちありがとう！

Answer 1

最後に、Style.Triggersを使用して、プッシュピンの色を変更する方法を見つけました。ここ は作業Geolocation.xaml次のとおりです。

<m:Map CredentialsProvider="XXX" Mode="Road"> 
    <m:MapItemsControl Name="Pushpins" ItemsSource="{Binding PushpinCollection}" > 
     <m:MapItemsControl.ItemTemplate> 
      <DataTemplate> 
       <m:Pushpin Location="{Binding Path=Location}" /> 
       <m:Pushpin.Style> 
        <Style TargetType="m:Pushpin"> 
         <Setter Property="Background" Value="Red" /> 
         <Style.Triggers> 
          <DataTrigger Binding="{Binding IsOnline}" Value="True"> 
           <Setter Property="Background" Value="Green" /> 
          </DataTrigger> 
         </Style.Triggers> 
        </Style> 
       <m:Pushpin.Style> 
      </DataTemplate> 
     </m:MapItemsControl.ItemTemplate> 
    </m:MapItemsControl> 
</m:Map> 

とGeolocationViewModel.csの作業バージョン：

namespace MyNamespace 
{ 
    internal class Pushpins : ObservableCollection<Pushpin> { } 

    internal class Pushpin : INotifyPropertyChanged 
    { 
     public Pushpin(double latitude, double longitude) 
     { 
      Location = new Location(latitude, longitude); 
      IsOnline = false; 
     } 
     public Location Location { get; set; } 

     private bool isOnline; 
     public bool IsOnline 
     { 
      get { return isOnline; } 
      set 
      { 
       isOnline = value; 
       OnPropertyChanged("IsOnline"); 
      } 
     } 

     #region IPropertyChange 
     public event PropertyChangedEventHandler PropertyChanged; 

     protected void OnPropertyChanged(string propertyName) 
     { 
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
     } 
     #endregion 
    } 

    internal class GeolocationViewModel : INotifyPropertyChanged 
    { 
     public GeolocationViewModel() 
     { 
      pushpinCollection = new Pushpins(); 
      CreateRandomPushpins(); 
     } 

     private Pushpins pushpinCollection; 
     public Pushpins PushpinCollection 
     { 
      get { return pushpinCollection; } 
     } 

     private void CreateRandomPushpins() 
     { 
      Random rnd = new Random(); 

      for (int i = 1; i <= 100; i++) 
      { 
       PushpinModel pin = new PushpinModel(rnd.NextDouble() * 180 - 90, rnd.NextDouble() * 360 - 180); 

       if (rnd.NextDouble() >= 0.5) 
        pin.IsOnline = true; 

       pushpinCollection.Add(pin); 
      } 
      OnPropertyChanged("PushpinCollection"); 
     } 

     #region IPropertyChange 
     public event PropertyChangedEventHandler PropertyChanged; 

     protected void OnPropertyChanged(string propertyName) 
     { 
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
     } 
     #endregion 
    } 
}