How to make a ListBox.ItemTemplate reusable/generic

Question

I am trying to understand how best to extend the ListBox control. As a learning experience, I wanted to build a ListBox whose ListBoxItems display a CheckBox instead of just text. I got that working in a basic fashion using the ListBox.ItemTemplate, explicitly setting the names of the properties I wanted to databind to. An example is worth a thousand words, so...

I've got a custom object for databinding:

public class MyDataItem {
    public bool Checked { get; set; }
    public string DisplayName { get; set; }

    public MyDataItem(bool isChecked, string displayName) {
        Checked = isChecked;
        DisplayName = displayName;
    }
}

(I build a list of those and set ListBox.ItemsSource to that list.) And my XAML looks like this:

<ListBox Name="listBox1">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <CheckBox IsChecked="{Binding Path=Checked}" Content="{Binding Path=DisplayName}" />
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

This works. But I want to make this template reusable, i.e. I'll want to bind to other objects with properties other than "Checked" and "DisplayName". How can I modify my template such that I could make it a resource, reuse it on multiple ListBox instances, and for each instance, bind IsChecked and Content to arbitrary property names?

Answer 1

The easiest way is probably to put the DataTemplate as a resource somewhere in your application with a TargetType of MyDataItem like this

<DataTemplate DataType="{x:Type MyDataItem}">
    <CheckBox IsChecked="{Binding Path=Checked}" Content="{Binding Path=DisplayName}" />
</DataTemplate>

You'll probably also have to include an xmlns to your local assembly and reference it through that. Then whenever you use a ListBox (or anything else that uses a MyDataItem in a ContentPresenter or ItemsPresenter) it will use this DataTemplate to display it.