How to set Itemsource to a Comobox Inside a DataTemplate Dynamically?

Question

I have one Listbox and applied one DataTemplate like this

<ListBox>
   <ListBox.ItemTemplate>
<Grid>
 <TextBlock Text="{Binding Path=Name}" Grid.Row=0/>
    <ComoboBox Name="test"
            DisplayMemberPath="Country"
            SelectedValuePath="Country_ID">
</Grid>

1. How will I load Itemsource to this Combobox dynamically based on each item selected in the Listbox. Iam new to WPF.. pls help with your valuable suggestions.

Answer 1

One way to do this is to bind the ItemsSource of your ComboBox to the SelectedValue property of the ListBox. For this to work the ListBox needs to be bound to a collection of items that contains a list of items that the ComboBox will bind to.

<ListBox
    x:Name="CategoryList"
    ItemsSource="{Binding Path=MasterList, 
        RelativeSource={RelativeSource AncestorType=Window}}"
    DisplayMemberPath="MasterProperty"
    SelectedValuePath="Details"
    />

<ComboBox
    ItemsSource="{Binding Path=SelectedValue, ElementName=CategoryList}"
    DisplayMemberPath="DetailProperty"
    Grid.Row="1"
    />

In this example I have created a public property in the code behind of the window that exposes a list of objects containing the Details collection.

public List<Master> MasterList { get; set; }

public class Master
{
    public string MasterProperty { get; set; }
    public List<Detail> Details { get; set; }
}

public class Detail
{
    public string DetailProperty { get; set; }
}

Answer 2

<ListBox>
  <ListBox.ItemTemplate>
   <Grid>
     <TextBlock Text="{Binding Path=Name}" Grid.Row=0/>
        <ComoboBox Name="test" 
           DataContent="{Binding RelativeSource={RelativeSource AncestorType=ListBox}}"                 
           ItemsSource="{Binding}"
        DisplayMemberPath="Country"
        SelectedValuePath="Country_ID">
   </Grid>

Now your combocbox is always have the same itemssource as the parent listbox.