在tabcontrol中将数据上下文分配给自动生成的Tabitem

Question

I am trying to assign an object to datacontext from TabItem. To get an idea, look at the following code sample

<UserControl x:Class="CustomCopyNas.UserControls.LoginUsers"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:igWindows="http://infragistics.com/Windows"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="300">

    <Grid Margin="5,0,5,0">
        <igWindows:XamTabControl Name="_xamTabControl"
             TabLayoutStyle="MultiRowSizeToFit"
             MaximumTabRows="4"
             MaximumSizeToFitAdjustment="50"
             MinimumTabExtent="100"
             InterTabSpacing="2"
             InterRowSpacing="2"
             Theme="Metro" 
             AllowTabClosing="False"
             TabItemCloseButtonVisibility="WhenSelectedOrHotTracked">
            <igWindows:XamTabControl.ContentTemplate>
                <DataTemplate>
                    <TextBox Text="{Binding Prop}"/>
                </DataTemplate>
            </igWindows:XamTabControl.ContentTemplate>
        </igWindows:XamTabControl>
    </Grid>
</UserControl>

As you can see, I use datatemplate for TabItem content appearance, TextBox. The TextBox Text property is binding to a property from the datacontext.

And the partial class from UserControl

public class Foo
{
    public string Prop {
        get { return "Hello Foo"; }
    }
}

/// <summary>
/// Interaction logic for LoginUsers.xaml
/// </summary>
public partial class LoginUsers : UserControl
{
    public LoginViewModel LoginViewModel = new LoginViewModel("file.xml");

    public LoginUsers()
    {
        InitializeComponent();

        foreach (var server in LoginViewModel.ServerUsers)
        {
            string header = server.Server;
            string name = "tabItem" + header;
            _xamTabControl.Items.Add(new TabItemEx() { Header = header, Name = name, DataContext = new Foo() });
        }
    }
}

As output on TabItem content I've got nothing, so emtpy content, why?

Answer 1

You don't seem to have declared your TabControl XAML properly. It is customary to see it defined more like this, using the TabControl.ItemsSource property:

<TabControl ItemsSource="{Binding YourCollectionProperty}">
    <TabControl.ItemTemplate> <!-- Header Template-->
        <DataTemplate>
            <TextBlock Text="{Binding HeaderText}" />
        </DataTemplate>
    </TabControl.ItemTemplate>
    <TabControl.ContentTemplate> <!-- Body Template-->
        <DataTemplate>
            <TextBlock Text="{Binding BodyText}" />
        </DataTemplate>
    </TabControl.ContentTemplate>
</TabControl>

For this to work, you'll need to create a custom class that has HeaderText and BodyText properties in it. Then you'll need to create a public ObservableCollection<YourCustomClass> collection property in your code behind named YourCollectionProperty .

Please note that the Binding s inside the two DataTemplate s will automatically have their DataContext s set to an item from the YourCollectionProperty collection and that is why your Binding to the Prop property didn't work.

Answer 2

Try moving the foreach loop so that it fires when the _xamTabControl.Loaded event fires. That should do the trick