Question

我有绑定问题。也许我没有看到它。

XAML文件

<ItemsControl Grid.Row="1" Grid.Column="1" x:Name="itemsControlTiles" ItemsSource="{Binding ProductCatalogLightList}" Margin="10">
            <ItemsControl.Template>
                <ControlTemplate>
                    <WrapPanel Width="800" HorizontalAlignment="Left"
                         FlowDirection="LeftToRight" IsItemsHost="true">
                    </WrapPanel>
                </ControlTemplate>
            </ItemsControl.Template>
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Controls:Tile Title="{Binding Name}"
                           Margin="3"
                           Background="{Binding Background}"
                           Style="{StaticResource PrdukteTileStyle}" >
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="Click">
                                <i:InvokeCommandAction Command="{Binding Source={StaticResource productsTileViewModel}, Path=DoSomethingCommand}" 
                                               CommandParameter="{Binding ID,ElementName= ProductCatalogLightList}" />

                            </i:EventTrigger>
                    </i:Interaction.Triggers>
                    </Controls:Tile>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>

所以我的问题是CommandParameter Binding。

我的ModelView看起来像那样

public class Product_Catalog_Light
{
    public string Name { get; set; }
    public string Description { get; set; }
    public int ID{ get; set; }
    public System.Windows.Media.Brush Background { get; set; }
}

public class ProductsTileViewModel : INotifyPropertyChanged
{
  private ObservableCollection<Product_Catalog_Light> _product_Catalog_LightList;
    public ProductsTileViewModel()
    {
        ProductCatalogLightList = new ObservableCollection<Product_Catalog_Light>();
    }
  ......
    public ObservableCollection<Product_Catalog_Light> ProductCatalogLightList
    {
        get { return _product_Catalog_LightList; }
        set
        {
            _product_Catalog_LightList = value;
            OnPropertyChanged("ProductCatalogLightList");
        }
    }

}

public ICommand DoSomethingCommand
    {
        get
        {
            return _doSomethingCommand ??
                   (_doSomethingCommand = new DelegateCommand<int>(ExecuteDoSomethingWithItem));
        }
    }

    private DelegateCommand<int> _doSomethingCommand;


    private void ExecuteDoSomethingWithItem(int db_ID )
    {
        // Do something wir the _id
        int i = 5;
    }

我收到一条错误消息，指出它无法找到绑定源。

System.Windows.Data错误：4：找不到绑定源引用'ElementName = ProductCatalogLightList'。 BindingExpression：路径= ID;的DataItem = NULL;目标元素是 'InvokeCommandAction'（HashCode = 11254959）;目标属性是 'CommandParameter'（类型'对象'）

Answer 1

您没有名为ProductCatalogLightList的元素，触发器中的datacontext也已经是Product_Catalog_Light，所以只需执行此操作：

CommandParameter="{Binding ID}"

绑定到xaml中控件的属性时使用ElementName，例如，如果您将Control命名为：Tile，则可以绑定到其Title属性

使用命令绑定故障ViewModel

1 个答案: