用集合填充组合框，而不是它所在的 Grid 绑定到的集合

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>

设置 Grid 的 DataContext 的 ItemTypes 来自包含另一个集合的 ViewModel。此网格内的制造商组合框需要填充其他集合。我试过这个：

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

但它没有用。如何让组合框填充除 Grid 绑定的集合之外的其他集合？

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 是视图模型中的一个属性。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

在其构造函数中分配给视图的数据上下文的内容。如果通过构造函数注入将view的datacontext指定为viewmodel，应该可以直接绑定为ItemsSource="{Binding companies}"

Answer 3

我想说只是不要在Grid 上设置DataContext。相反，单独绑定每个项目。除非您提供更多信息 - 特别是您的虚拟机，否则很难提供进一步的建议。