Question

我有以下代码：

<Grid DataContext="{Binding ItemTypes}">
            ...

            <TextBlock Text="Name:" />
            <TextBox Grid.Column="2" Text="{Binding Name}" />

            <TextBlock Grid.Row="1" Text="Description:" />
            <TextBox Grid.Column="1" Grid.Row="1" Text="{Binding Description}" />

            <TextBlock Grid.Row="2" Text="Manufacturer:" />
            <ComboBox Grid.Column="1" Grid.Row="2" />

            <TextBlock Grid.Row="3" Text="Short Name:" />
            <TextBox Grid.Column="1" Grid.Row="3" Text="{Binding ShortName}" />
        </Grid>

Grid的DataContext设置的ItemTypes来自一个包含另一个集合的ViewModel。此Grid中的制造商Combobox需要填充其他集合。我试过这个：

     ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor,
 AncestorType=Window, AncestorLevel=1}, Path=DataContext.companies}"

但它没有用。如何让组合框填充其他集合而不是Grid绑定的集合？

ViewModel代码：

    public class ItemTypeViewModel
    {
        #region private fields
        private ICollectionView collectionView;
        private IItemTypeService itemTypeService;
        #endregion

        #region automatic properties
        public ObservableCollection<ItemTypeViewModel> ItemTypes { get; private set; }
        public IEnumerable<Company> companies { get; private set; }
        #endregion properties

        #region constructors
        public ItemTypeAdminViewModel(IItemTypeService itemTypeService)
        {
            this.itemTypeService = itemTypeService;
            Initialize();
            collectionView = CollectionViewSource.GetDefaultView(ItemTypes);
        }
        #endregion

        #region private methods
        private void Initialize()
        {
            //TODO figure out if I should I wrap in Try/Catch here
            ItemTypes = new ObservableCollection<ItemTypeViewModel>(itemTypeService.GetItemTypes());
            companies = itemTypeService.GetCompanies();
        }
        #endregion

        #region commands
        public ICommand GoToFirst
        {
            get
            {
                return new RelayCommand(() => collectionView.MoveCurrentToFirst(),
                    () => collectionView.CurrentPosition >= 1);
            }
        }

        public ICommand GoToLast
        {
            get
            {
                return new RelayCommand(() => collectionView.MoveCurrentToLast(),
                    () => collectionView.CurrentPosition < (ItemTypes.Count - 1));
            }
        }

        public ICommand NextCommand
        {
            get
            {
                return new RelayCommand(() => collectionView.MoveCurrentToNext(),
                    () => collectionView.CurrentPosition < (ItemTypes.Count - 1));
            }
        }

        public ICommand PreviousCommand
        {
            get
            {
                return new RelayCommand(() => collectionView.MoveCurrentToPrevious(),
                    () => collectionView.CurrentPosition >= 1);
            }
        }
        #endregion
    }
}

Answer 1

假设您的视图模型设置为Window.DataContext，而您的其他集合MyOtherCollection是视图模型中的属性。将您的ComboBox更改为以下内容：

<ComboBox Grid.Column="1" Grid.Row="2"
          ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Window}, Path=DataContext.MyOtherCollection}" />

Answer 2

我想说的是，不要在DataContext上设置Grid。而是单独绑定每个项目。除非您提供进一步的信息，特别是您的VM，否则很难提供进一步的建议。

Answer 3

在构造函数中为视图的datacontext分配了什么。如果通过构造函数注入将视图的datacontext指定为viewmodel，则应该能够直接绑定为ItemsSource="{Binding companies}"

使用除了Grid所绑定的集合之外的集合来填充组合框

3 个答案: