C# WPF MVVM ItemsControl双层嵌套

View界面 

<ItemsControl ItemsSource="{Binding ParentButtons}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <StackPanel Orientation="Vertical"/>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>

    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Border BorderBrush="Gray" BorderThickness="1" Margin="5" Padding="5">
                <StackPanel>
                    <!-- 父 Button -->
                    <Button Content="{Binding ParentName}" 
                        Background="LightBlue"
                        Height="40"
                        FontWeight="Bold"/>

                     <!--子 ItemsControl 生成多个子 Button--> 
                    <ItemsControl ItemsSource="{Binding ChildButtons}" Margin="20,5,5,5">
                        <ItemsControl.ItemsPanel>
                            <ItemsPanelTemplate>
                                <WrapPanel/>
                            </ItemsPanelTemplate>
                        </ItemsControl.ItemsPanel>

                        <ItemsControl.ItemTemplate>
                            <DataTemplate>
                                <Button Content="{Binding ChildName}" 
                                    Margin="5" 
                                    Width="100"
                                    Background="LightGreen"/>
                            </DataTemplate>
                        </ItemsControl.ItemTemplate>
                    </ItemsControl>
                </StackPanel>
            </Border>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

Viewmodel 构造函数

ParentButtons = new List<ParentButton>
{
    new ParentButton
    {
        ParentName = "Parent Button 1",
        ChildButtons = new List<ChildButton>
        {
            new ChildButton { ChildName = "Child 1.1" },
            new ChildButton { ChildName = "Child 1.2" },
            new ChildButton { ChildName = "Child 1.3" }
        }
    },
    new ParentButton
    {
        ParentName = "Parent Button 2",
        ChildButtons = new List<ChildButton>
        {
            new ChildButton { ChildName = "Child 2.1" },
            new ChildButton { ChildName = "Child 2.2" },
            new ChildButton { ChildName = "Child 2.3" },
            new ChildButton { ChildName = "Child 2.4" }
        }
    },
    new ParentButton
    {
        ParentName = "Parent Button 3",
        ChildButtons = new List<ChildButton>
        {
            new ChildButton { ChildName = "Child 3.1" },
            new ChildButton { ChildName = "Child 3.2" }
        }
    }
};

定义属性

public List<ParentButton> ParentButtons { get; set; }

public class ParentButton
{
    public string ParentName { get; set; }
    public List<ChildButton> ChildButtons { get; set; }
}

public class ChildButton
{
    public string ChildName { get; set; }
}