Question

I have a non-MVVM application. In the MainWindow, I have a TabControl with several tabs, and each tab contains a UserControl. Because those UserControls have similar features, I derive them from a base class that inherits from UserControl. Each of the UserControls has a TextBox called EdiContents. And each of them has a button:

<Button Name="Copy" Content="Copy to Clipboard" Margin="10" Click="Copy_Click" />

I would like to implement Copy_Click in the base UserControl class:

private void Copy_Click(object sender, RoutedEventArgs e)
{
    System.Windows.Forms.Clipboard.SetText(EdiContents.Text);
}

But the base class doesn’t know EdiContents TextBox, which is declared in each UserControl’s XAML. Could you please suggest how this can be solved?

Thanks.

Answer 1

You can do something like this.

public partial class DerivedUserControl : BaseUserControl
{
    public DerivedUserControl()
    {
        InitializeComponent();
        BaseInitComponent();
    }
}

Note that you are calling BaseInitComponent after InitializeComponent

XAML behind for derived control

<app:BaseUserControl x:Class="WpfApplication5.DerivedUserControl"
                     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:app="clr-namespace:WpfApplication5"
                     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
                     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
                     >
    <Grid>
        <Button Name="CopyButton"/>
    </Grid>
</app:BaseUserControl>

In your BaseUserControl::BaseInitComponent you simply lookup the button by name and wire up the event.

public class BaseUserControl : UserControl
{
    public void BaseInitComponent()
    {
        var button = this.FindName("CopyButton") as Button;
        button.Click += new System.Windows.RoutedEventHandler(Copy_Click);
    }

    void Copy_Click(object sender, System.Windows.RoutedEventArgs e)
    {
        //do stuff here
    }
}