Can one bind a combobox Itemssource from a datatemplate of a ItemsControl

问题

Given ComboBox in the ItemsControl will have different items which is based on the DataContext of the item (not of the ItemsControl). Can it be done? And how? Preferably from code behind.

I have the following DataModel:

class Tester
{
    public Tester(string name, string surname)
    {
        Name = name;
        Surname = surname;
    }

    public string Name { get; set; }
    public string Surname { get; set; }
    public override string ToString()
    {
        return Name + " " + Surname;
    }
}

class TheT
{
    public ObservableCollection<Tester> TesterObject;

    public TheT()
    {
        TesterObject = new ObservableCollection<Tester>();
    }

    public string myDisplayName { get { return "test"; } }

    public void Add(Collection<Tester> col)
    {
        TesterObject.Clear();
        foreach (Tester t in col) { TesterObject.Add(t); }
    }
}

In Window code I have:

ObservableCollection<TheT> myDataV ;
Public MainWindow()
{
    InitializeComponent();

    ObservableCollection<Tester> Tester1 = new ObservableCollection<Tester>();
    Tester1.Add(new Tester("Sunny", "Jenkins"));
    Tester1.Add(new Tester("Pieter", "Pan"));

    ObservableCollection<Tester> Tester2 = new ObservableCollection<Tester>();
    Tester2.Add(new Tester("Jack", "Sanders"));
    Tester2.Add(new Tester("Bill", "Trump"));

    myDataV = new ObservableCollection<TheT>();
    myDataV.Add(new TheT(Tester1));
    myDataV.Add(new TheT(Tester2));

    IControl.ItemsSource = myDataV;
    IControl.ItemTemplate = TestingDT;
}

IControl being an ItemsControl set up in XAML:

<ItemsControl x:Name="IControl" Margin="53,375,81,63">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <VirtualizingStackPanel Orientation="Horizontal"/>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
</ItemsControl>

And DataTemplate that I have tried all kinds of ways. But still do not get items to show like below:

// the DataTemplate
private DataTemplate TestingDT
{
    get
    {
        DataTemplate DFT = new DataTemplate();
        DFT.DataType = typeof(TheT);

        FrameworkElementFactory Item = new FrameworkElementFactory(typeof(ComboBox));

        Binding B = new Binding("TesterObject")
        {
            Source = this
        };

        Item.SetBinding(ComboBox.ItemsSourceProperty, B);
        //Item.SetValue(ComboBox.DisplayMemberPathProperty, "Name");

        DFT.VisualTree = Item;
        return DFT;
    }
}

回答1:

with this little changes you should get your expected result

public class Tester {
  public Tester(string name, string surname) {
    Name = name;
    Surname = surname;
  }

  public string Name { get; set; }

  public string Surname { get; set; }

  public override string ToString() {
    return Name + " " + Surname;
  }
}

public class TheT : DependencyObject {
  public static readonly DependencyProperty TesterObjectProperty =
    DependencyProperty.Register("TesterObject", typeof(ObservableCollection<Tester>), typeof(TheT),
                                new FrameworkPropertyMetadata());

  public ObservableCollection<Tester> TesterObject {
    get { return (ObservableCollection<Tester>)GetValue(TesterObjectProperty); }
    set { SetValue(TesterObjectProperty, value); }
  }

  public TheT(Collection<Tester> col) {
    TesterObject = new ObservableCollection<Tester>();
    foreach (Tester t in col) { TesterObject.Add(t); }
  }

  public void Add(Collection<Tester> col) {
    TesterObject.Clear();
    foreach (Tester t in col) { TesterObject.Add(t); }
  }
}

public Window1()
{
  InitializeComponent();

  ObservableCollection<Tester> Tester1 = new ObservableCollection<Tester>();
  Tester1.Add(new Tester("Sunny", "Jenkins"));
  Tester1.Add(new Tester("Pieter", "Pan"));

  ObservableCollection<Tester> Tester2 = new ObservableCollection<Tester>();
  Tester2.Add(new Tester("Jack", "Sanders"));
  Tester2.Add(new Tester("Bill", "Trump"));

  var myDataV = new ObservableCollection<TheT>();
  myDataV.Add(new TheT(Tester1));
  myDataV.Add(new TheT(Tester2));

  IControl.ItemsSource = myDataV;
}

xaml

<Window x:Class="stackoverflow.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:stackoverflow"
        Title="stackoverflow"
        Height="300"
        Width="300">

  <Grid>

    <ItemsControl x:Name="IControl" Margin="10">
      <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
          <VirtualizingStackPanel Orientation="Horizontal"/>
        </ItemsPanelTemplate>
      </ItemsControl.ItemsPanel>
      <ItemsControl.ItemTemplate>
        <DataTemplate DataType="{x:Type local:TheT}">
          <ComboBox ItemsSource="{Binding TesterObject}"
                    MinWidth="80"
                    DisplayMemberPath="Name" />
        </DataTemplate>
      </ItemsControl.ItemTemplate>
    </ItemsControl>

  </Grid>

</Window>

hope that helps

来源：https://stackoverflow.com/questions/17555458/can-one-bind-a-combobox-itemssource-from-a-datatemplate-of-a-itemscontrol