通过MVVM命令访问集合

Question

在我的ViewModel中，我拥有包含Observable Collection of Cards的基类和Deck类。下面是它是如何在XAML绑定

 <GridView ItemsSource="{Binding DeckCollection}" IsItemClickEnabled="True" Grid.Row="0"> 
      <GridView.ItemTemplate> 
       <DataTemplate> 
        <Button Command="{Binding Path=??}" 
          CommandParameter=?? 
         <Button.Content> 
          <Grid> 
           <Image 
            Source="{Binding ImagePath}" 
            Stretch="None"/> 
          </Grid> 
         </Button.Content> 
        </Button> 
       </DataTemplate> 
      </GridView.ItemTemplate> 
     </GridView> 

这里是我的班

class Deck 
{ 
    private ObservableCollection<Card> _deckCollection = new ObservableCollection<Card>(); 
    public ObservableCollection<Card> DeckCollection 
    { 
     get { return _deckCollection; } 
     set { _deckCollection = value; } 
    } 

    public Deck() 
    { 
     ActionCommand = new MyCommand(); 
     ActionCommand.CanExecuteFunc = obj => true; 
     ActionCommand.ExecuteFunc = AddToList; 
    } 


    public void AddToList(object parameter) 
    { 
     var clickedCard = this; 
     //add Card to list which in this case is not possible 
     //DeckCollection.Add(this) ? 
    } 
} 

class Card 
{ 
    public String Name { get; set; } 
    public int Cost { get; set; } 
    public String ImagePath { get; set; } 
    public MyCommand ActionCommand { get; set; } 
} 

而且还mycommand的类

public class MyCommand : ICommand 
{ 

    public Predicate<object> CanExecuteFunc { get; set; } 
    public Action<object> ExecuteFunc { get; set; } 

    public bool CanExecute(object parameter) 
    { 
     return CanExecuteFunc(parameter); 
    } 

    public event EventHandler CanExecuteChanged; 
    public void Execute(object parameter) 
    { 
     ExecuteFunc(parameter); 
    } 
} 

我做了修改建议，但现在ActionCommand不中可见集合，因为只有属于Card类的属性才能绑定。

编辑：我改变了我的XAML文件下却得到了一些错误

<Button Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:Deck}, Path=ActionCommand}}"> 

属性“AncestorType”型“的RelativeSource”没有被发现。

在'RelativeSource'类型中未找到'Path'属性。

成员“AncestorType”未被识别或无法访问。

成员“路径”未被识别或无法访问。

未知的成员元素“AncestorType“的RelativeSource”

未知的成员“路径”元素“的RelativeSource”

请帮

Answer 1

如果你想有按钮，增加了新的项目，你的收集，我认为这样的东西可能是解决方案。

在XAML：

<GridView ItemsSource="{Binding DeckCollection}" IsItemClickEnabled="True" Grid.Row="0"> 
     <GridView.ItemTemplate> 
      <DataTemplate> 
       <Button> 
        <Button.Content> 
         <Grid> 
          <Image Source="{Binding ImagePath}" 
           Stretch="None"/> 
         </Grid> 
        </Button.Content> 
       </Button> 
      </DataTemplate> 
     </GridView.ItemTemplate> 
    </GridView> 
<!-- public property located in Deck class --> 
<Button Command="{Binding AddItemCommand}" Content="Add Item"/> 

在C＃：

class Deck, INotifyPropertyChanged /*custom implementation depends on .NET version, in my case its .NET3.5*/ 
    { 
    private ObservableCollection<Card> _deckCollection = new ObservableCollection<Card>(); 
    public ObservableCollection<Card> DeckCollection 
    { 
     get { return _deckCollection; } 
     set { _deckCollection = value; 
       OnPropertyChanged(() => DeckCollection); } 
    } 

    // your Add command 
    public ICommand AddItemCommand { get { return new MyCommand(AddToList); } } 
    private void AddToList(object parameter) 
    { 
     DeckCollection.Add(new Card()); 
    } 

    public Deck() { } 

    public event PropertyChangedEventHandler PropertyChanged; 
    protected void OnPropertyChanged<T>(Expression<Func<T>> expression) 
    { 
     if (PropertyChanged == null) return; 

     var body = (MemberExpression)expression.Body; 
     if (body != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs(body.Member.Name)); 
    } 
} 

在这种情况下，主要的事情是，你不能有集里面添加按钮。