在ObservableCollection中绑定ObservableCollection

Question

我刚刚学会了如何将ComboBox绑定到ObservableCollection。喔呼！是否有方法将第二个ComboBox绑定到第一个ComboBox的选定集合？因此，每个项目都有一个ObservableCollection的Peices。当您选择一个项目时，我希望第二个ComboBox显示所选项目的代码！

public class Section
{
    public ObservableCollection<Item> Items { get; set; }

    public Section()
    {
        Items = new ObservableCollection<Item>();
    }

    public void AddItem()
    {
        string id = Items.Count.ToString();
        Items.Add(new Item("Item " + id));
    }
}

public class Item
{
    private string _name;

    public ObservableCollection<Peice> Peices { get; set; }

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }

    public Item(string name)
    {
        _name = name;
        Peices = new ObservableCollection<Peice>();
    }

    public void AddPeice()
    {
        string id = Peices.Count.ToString();
        Peices.Add(new Peices("Peice " + id));
    }
}

public class Peice
{
    private string _name;

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }

    public Peices(string name)
    {
        _name = name;
    }
}

<Grid>
    <ComboBox x:Name="cbItems" ItemsSource="{Binding Items}" DisplayMemberPath="Name" HorizontalAlignment="Left" Height="23" Margin="10,10,0,0" VerticalAlignment="Top" Width="120"/>
    <Button x:Name="button" Content="Add" HorizontalAlignment="Left" Margin="55,33,0,0" VerticalAlignment="Top" Width="75" Click="AddItem"/>

    <ComboBox x:Name="cbPeices" ItemsSource="{Binding Item.Peices}" DisplayMemberPath="Name" HorizontalAlignment="Left" Margin="10,72,0,0" VerticalAlignment="Top" Width="120"/>
    <Button x:Name="button1" Content="Add" HorizontalAlignment="Left" Margin="55,94,0,0" VerticalAlignment="Top" Width="75"/>
</Grid>

更新： Ok，所以条目是'Item‘的列表。项目有一个'Peice‘的列表。我希望combobox 2显示所选项目的Peices集合的内容。

Answer 1

绑定到第一个组合框的选定项，如下所示：

<ComboBox x:Name="comboBox1" ItemsSource="{Binding Items}" Width="150" Height="30" DisplayMemberPath="Name"></ComboBox>
<ComboBox ItemsSource="{Binding SelectedItem.Peices, ElementName=comboBox1}" Width="150" Height="30" DisplayMemberPath="Name"></ComboBox>

Answer 2

只需将两者绑定到相同的事物，但添加双向绑定模式。所以：

<Grid>
    <ComboBox x:Name="cbItems" ItemsSource="{Binding Items, Mode=TwoWay, 
                UpdateSourceTrigger=PropertyChanged}" DisplayMemberPath="Name" 
                HorizontalAlignment="Left" Height="23" Margin="10,10,0,0" 
                VerticalAlignment="Top" Width="120"/>
    <Button x:Name="button" Content="Add" HorizontalAlignment="Left" Margin="55,33,0,0" 
                VerticalAlignment="Top" Width="75" Click="AddItem"/>

    <ComboBox x:Name="cbPeices" ItemsSource="{Binding Items, Mode=TwoWay,
                    UpdateSourceTrigger=PropertyChanged}" DisplayMemberPath="Name" 
                HorizontalAlignment="Left" Margin="10,72,0,0" VerticalAlignment="Top" 
                Width="120"/>
    <Button x:Name="button1" Content="Add" HorizontalAlignment="Left" Margin="55,94,0,0" 
                VerticalAlignment="Top" Width="75"/>
</Grid>

Answer 3

尝尝这个,

<ComboBox x:Name="cbItems" ItemsSource="{Binding Items, Mode=TwoWay, 
            UpdateSourceTrigger=PropertyChanged}" DisplayMemberPath="Name" 
            HorizontalAlignment="Left" Height="23" Margin="10,10,0,0" 
            VerticalAlignment="Top" Width="120"/>


<ComboBox x:Name="cbPeices" ItemsSource="{Binding Items, Mode=TwoWay,
                UpdateSourceTrigger=PropertyChanged}" 
          DisplayMemberPath="Name" SelectedItem="{Binding ElementName=cbItems, Path=SelectedItem}"
            HorizontalAlignment="Left" Margin="10,72,0,0" VerticalAlignment="Top" 
            Width="120"/>