How do I access elements that have been dynamically assigned to a control in the form of an XAML resource?

I have the following resource in my window that declares how a certain kind of TabItem should look like.

<Window.Resources>
    <StackPanel x:Key="TabSearchContents" x:Shared="False"
    Orientation="Vertical">
    <Border
        BorderThickness="3"
        BorderBrush="Purple">
        <TextBlock
            Text="SEARCH BOOKS"
        开发者_StackOverflow社区    FontFamily="Verdana"
            FontSize="25"
            Foreground="Blue"
            HorizontalAlignment="Center" />
    </Border>
    <StackPanel
        Height="30"
        Orientation="Horizontal"
        Margin="5">

        <TextBox
            x:Name="txtSearch"
            Width="650"
            FontFamily="Comic Sans MS"
            Foreground="Chocolate" />
        <Button
            x:Name="btnSearch"
            Width="100"
            Content="Go!"
            Click="BtnSearch_Click" />
    </StackPanel>
    <Grid x:Name="gridResults">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="450"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <ScrollViewer Grid.Column="0" VerticalScrollBarVisibility="Auto">
        <ItemsControl x:Name="itmsSearch" ItemsSource="{Binding}" Padding="4"
                ItemTemplate="{StaticResource SearchResultItemDT}">         
        </ItemsControl>
        </ScrollViewer>
        <StackPanel x:Name="stkpnlDetails">

        </StackPanel>
    </Grid>
</StackPanel>
</Window.Resources>

Then, in my code-behind, I dynamically create a tab and assign to the TabControl that is already present in my window.

    void BtnNewTab_Click(object sender, RoutedEventArgs e)
    {
        TabItem tb = new TabItem();
        tb.Content = this.Resources["TabSearchContents"];               
        tb.DataContext = _bridge.SearchBooksByTitle("e");           

        tb.Header = "Wuttp yo!";
        Button btnGo = ((Button)tb.FindName("btnSearch"));
        ItemsControl i = (ItemsControl)tb.FindName("itmsSearch");
        btnGo.Resources.Add("ResultList", i);

        daTabs.Items.Add(tb);
        tb.Focus();


    }

I want to access the btnSearch Button that is declared in my XAML resource.

As it is, this code throws an exception since btnGo turns out to be null (as well as i) since it can't find the expected control via FindName().

I read about the RegisterName() method, but it requires a reference to an instance of the required control... which I don't have.

I dont think you should define your button like this, try defining it in a style, creating a button and assigning the button that style, i think you will be able to get what you are going for this way.

myTheme.xaml

<ResourceDictionary
       <Style x:Key="btnSearch" TargetType="{x:Type Button}">
            <Setter Property="Width" Value="100"/>
            <Setter Property="Content" Value="Go!"/>
            <Setter Property="Click" Value="btn_Click"/>
       </Style>
ResourceDictionary/>

myCode.cs

Button btnGo = new Button;
btnGo.Style = "{DynamicResource btnSearch}";

Hope this helps, Eamonn