Silverlight关联两个数据网格

我的问题:如何将SelectedItem从主数据网格绑定到辅助数据网格的ItemsSource?

详细内容: 我的视图中有两个数据网格。第一个显示团队的集合,第二个显示所选团队中的人员列表。

选定团队 属性已正确更新,但人员网格未填充。

注意:我不能使用嵌套网格,也不能使用SL数据网格中提供的酷主细节功能。

更新: 为什么ComboBox.SelectedItem和DataGrid.SelectedItem的行为会如此不同?

做记号

视图:

<UserControl x:Class="NestedDataGrid.MainPage"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data">
    <StackPanel x:Name="LayoutRoot">
        <TextBlock Text="Teams:" />
        <data:DataGrid ItemsSource="{Binding Teams}"
                       SelectedItem="{Binding SelectedTeam, Mode=TwoWay}"
                       AutoGenerateColumns="False">
            <data:DataGrid.Columns>
                <data:DataGridTextColumn Header="Id" Binding="{Binding TeamId}" />
                <data:DataGridTextColumn Header="Desc" Binding="{Binding TeamDesc}" />
            </data:DataGrid.Columns>
        </data:DataGrid>
        <TextBlock Text="Peeps:" />
        <data:DataGrid ItemsSource="{Binding SelectedTeam.People}"
                       AutoGenerateColumns="False">
            <data:DataGrid.Columns>
                <data:DataGridTextColumn Header="Id"
                                         Binding="{Binding PersonId}" />
                <data:DataGridTextColumn Header="Name"
                                         Binding="{Binding Name}" />
            </data:DataGrid.Columns>
        </data:DataGrid>
    </StackPanel>
</UserControl>

using System.Windows.Controls;
namespace NestedDataGrid
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
            this.LayoutRoot.DataContext = new ViewModel();
        }

    }
}

视图模型:

using System.Collections.ObjectModel;
namespace NestedDataGrid
{
    public class ViewModel: ObjectBase
    {
        public ViewModel()
        {
            ObservableCollection<Person> RainbowPeeps = new ObservableCollection<Person>()
            {
                new Person(){ PersonId=1, Name="George"}, 
                new Person(){ PersonId=2, Name="Zippy"}, 
                new Person(){ PersonId=3, Name="Bungle"}, 
            };

            ObservableCollection<Person> Simpsons = new ObservableCollection<Person>()
            {
                new Person(){ PersonId=4, Name="Moe"}, 
                new Person(){ PersonId=5, Name="Barney"}, 
                new Person(){ PersonId=6, Name="Selma"}, 
            };

            ObservableCollection<Person> FamilyGuyKids = new ObservableCollection<Person>()
            {
                new Person(){ PersonId=7, Name="Stewie"}, 
                new Person(){ PersonId=8, Name="Meg"}, 
                new Person(){ PersonId=9, Name="Chris"}, 
            };


            Teams = new ObservableCollection<Team>()
            {
                new Team(){ TeamId=1, TeamDesc="Rainbow", People=RainbowPeeps},
                new Team(){ TeamId=2, TeamDesc="Simpsons", People=Simpsons},
                new Team(){ TeamId=3, TeamDesc="Family Guys", People=FamilyGuyKids },
            };
        }


        private ObservableCollection<Team> _teams;
        public ObservableCollection<Team> Teams
        {
            get { return _teams; }
            set
            {
                SetValue(ref _teams, value, "Teams");
            }
        }


        private Team _selectedTeam;
        public Team SelectedTeam
        {
            get { return _selectedTeam; }
            set
            {
                SetValue(ref _selectedTeam, value, "SelectedTeam");
            }
        }


    }
}

相关类别:

using System;
using System.ComponentModel;

namespace NestedDataGrid
{
    public abstract class ObjectBase : Object, INotifyPropertyChanged
    {
        public ObjectBase()
        { }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void _OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler pceh = PropertyChanged;
            if (pceh != null)
            {
                pceh(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        protected virtual bool SetValue<T>(ref T target, T value, string propertyName)
        {
            if (Object.Equals(target, value))
            {
                return false;
            }

            target = value;
            _OnPropertyChanged(propertyName);

            return true;
        }

    }


    public class Person: ObjectBase
    {
        private int  _personId;
        public int PersonId
        {
            get { return _personId; }
            set
            {
                SetValue(ref _personId, value, "PersonId");
            }
        }

        private string _name;
        public string Name
        {
            get { return _name; }
            set
            {
                SetValue(ref _name, value, "Name");
            }
        }

    }

    public class Team : ObjectBase
    {

        private int _teamId;
        public int TeamId
        {
            get { return _teamId; }
            set
            {
                SetValue(ref _teamId, value, "TeamId");
            }
        }

        private string _teamDesc;
        public string TeamDesc
        {
            get { return _teamDesc; }
            set
            {
                SetValue(ref _teamDesc, value, "TeamDesc");
            }
        }


        private ObservableCollection<Person> _people;
        public ObservableCollection<Person> People
        {
            get { return _people; }
            set
            {
                SetValue(ref _people, value, "People");
            }
        }

    }
}

用组合框替换第一个数据网格,一切正常。为什么DataGrid.SelectedItem和ComboBox.SelectedItem的行为会如此不同?

<StackPanel x:Name="LayoutRoot">        
    <TextBlock Text="Teams:" />
    <ComboBox SelectedItem="{Binding SelectedTeam, Mode=TwoWay}"
                    ItemsSource="{Binding Teams}"/>
    <TextBlock Text="{Binding SelectedTeam}" />    
    <TextBlock Text="Peeps:" />
    <data:DataGrid ItemsSource="{Binding SelectedTeam.People}" />    
</StackPanel>