ReactiveUI ReactiveList和的DependencyProperty

我使用ReactiveUI ReactiveLists，在我的項目，這ReactiveLists之一綁定到ItemsSourceDependencyProperty在我的自定義WPF MultiSelectComboBox：ReactiveUI ReactiveList和的DependencyProperty

<CustomControls:MultiSelectComboBox x:Name="CountriesCombobox" 
         Width="200" 
         VerticalContentAlignment="Center" 
         ItemsSource="{Binding Repository.Countries}" 
         SelectedItems="{Binding Repository.SearchViewSelectedCountries, Mode=TwoWay}"/>

...

public static readonly DependencyProperty ItemsSourceProperty = 
     DependencyProperty.Register("ItemsSource", typeof(IEnumerable<object>), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null, 
    new PropertyChangedCallback(MultiSelectComboBox.OnItemsSourceChanged))); 

public static readonly DependencyProperty SelectedItemsProperty = 
    DependencyProperty.Register("SelectedItems", typeof(IEnumerable<object>), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null, 
new PropertyChangedCallback(MultiSelectComboBox.OnSelectedItemsChanged))); 

public IEnumerable<object> SelectedItems 
{ 
    get { return (IEnumerable<object>)GetValue(SelectedItemsProperty); } 
    set { SetValue(SelectedItemsProperty, value); } 
} 

public IEnumerable<object> ItemsSource 
{ 
    get { return (IEnumerable<object>)GetValue(ItemsSourceProperty); } 
    set { SetValue(ItemsSourceProperty, value); } 
}

而在我的ComboBox中選擇一個選項後SetSelectedItems方法被稱爲：

private void SetSelectedItems() 
{ 
    if (SelectedItems == null) 
     SelectedItems = new List<object>(); 

    foreach (Node node in _nodeList) 
    { 
     if (node.IsSelected && node.Title != "All") 
     { 
      if (this.ItemsSource.Count() > 0) 
      { 
       var temp = SelectedItems.ToList(); 
       temp.Add(this.ItemsSource.First(x => x.ToString() == node.Title)); 
       SelectedItems = SelectedItems.Concat(temp); 
      } 
     } 
    } 
}

在這裏，我嘗試添加SelectedItems到SelectedItemsProperty，我的問題是，如果我的ItemsSourceProperty有不同的類型比IEnumerable結合沒有工作和財產是空的（我曾經嘗試類型：List，IList，ICollection， ReactiveList，IReactiveList），如果它是作爲IEnumerableSystem.InvalidCastException被拋出時，我試圖投SelectedItems列出：

var temp1 = (List<object>)SelectedItems;

如果我將嘗試使用Concat方法樣以上，SelectedItems設置爲null。所以我的問題是我如何添加alements到SelectedItems當它被綁定到ReactiveList？

它的建立accordig到this文章。

來源

2017-01-30 Carlos28

嘗試使SelectedItems一個ObservableCollection。順便說一句，我認爲持有對象類型的集合是不錯的做法。 –

改變到的ObservableCollection我的列表後是空的，不知何故結合沒有工作 – Carlos28

對不起，也許我失去了一些東西，但如果是ReactiveList這裏？此外，在您複製的示例中，SelectedItems屬性被定義爲Dictionary（指出可以使用List），爲什麼將其更改爲IEnumerable？ –

好，它的工作我用IList後的界面：

public static readonly DependencyProperty ItemsSourceProperty = 
     DependencyProperty.Register("ItemsSource", typeof(IList), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null, 
    new PropertyChangedCallback(MultiSelectComboBox.OnItemsSourceChanged))); 

public static readonly DependencyProperty SelectedItemsProperty = 
     DependencyProperty.Register("SelectedItems", typeof(IList), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null, 
    new PropertyChangedCallback(MultiSelectComboBox.OnSelectedItemsChanged))); 

public IList ItemsSource 
{ 
    get { return (IList)GetValue(ItemsSourceProperty); } 
    set { SetValue(ItemsSourceProperty, value); } 
} 

public IList SelectedItems 
{ 
    get { return (IList)GetValue(SelectedItemsProperty); } 
    set { SetValue(SelectedItemsProperty, value); } 
}

然後：

private void SetSelectedItems() 
{ 
    SelectedItems.Clear(); 

    foreach (Node node in _nodeList) 
    { 
     if (node.IsSelected && node.Title != "All") 
     { 
      if (this.ItemsSource.Count > 0) 
       SelectedItems.Add(this.ItemsSource.Cast<object>().ToList().First(x => x.ToString() == node.Title)); 
     } 
    } 
}

來源

2017-01-30 12:50:21 Carlos28

ReactiveUI ReactiveList和的DependencyProperty

回答

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