Adding TabItems dynamically

Question

I have a TabControl control

<TabControl Name="Farms_myVillages"
            ItemsSource="{Binding Villages}">
</TabControl/>

In the code behind I add some tabs dynamically to the TabControl as follows:

foreach (Village vill in Villages)
{
    TabItem tab = new TabItem();
    tab.Header = vill.Name;
    VillageUserControl c = new VillageUserControl();
    c.DataContext = vill;
    tab.Content = c;
    Farms_myVillages.Items.Add(tab);
}

where VillageUserControl is a UserControl that deal with the specified village. This code works fine and it gets the expected results...

The problem is that I don't want this to be in the code behind but just in the xaml itself.

I try this:

<TabControl Name="Farms_myVillages"
            ItemsSource="{Binding Villages}">
      <TabControl.ItemContainerStyle>
          <Style TargetType="TabItem">
              <Setter Property="Header" Value="{Binding Name}"/>
              <Setter Property="Content">
                 <Setter.Value>
                    <u:VillageUserControl DataContext="{Binding}"/>
                 </Setter.Value>
              </Setter>
          </Style>
      </TabControl.ItemContainerStyle>
</TabControl>

After I run it, it throws an exception: "Specified element is already the logical child of another element. Disconnect it first."

Did I miss something? Please help me here...

Answer 1

You set the wrong thing, you should not modify the ItemContainerStyle but the TabControl.ItemTemplate for the header and TabControl.ContentTemplate for the content.

(The exception may have to do with the fact that in the style only one VillageUserControl is created, but the style applies to multiple tab items.)

Answer 2

Now it is working:

<TabControl Name="Farms_myVillages" 
           ItemsSource="{Binding Villages}">
       <TabControl.ItemTemplate>
            <DataTemplate>
                 <TextBlock Text="{Binding Name}"/>
            </DataTemplate>
       </TabControl.ItemTemplate>
      <TabControl.ContentTemplate>
            <DataTemplate>
                <u:VillageResources/>
            </DataTemplate>
      </TabControl.ContentTemplate>
</TabControl>

Answer 3

Your approach of not having this in code behind is right, instead of using ItemContainerStyle use ItemTemplate and ContentTemplate. You can have a look at this sample from Josh Smith for creating a tabs using Templates and Styles -

http://code.msdn.microsoft.com/mag200902MVVM/Release/ProjectReleases.aspx?ReleaseId=2026