WPF - Very basic ListBox.ItemTemplate Question

ItemTemplate wont work when you put ListBoxItem directly as items. General concept is you databind a CRL collection to the ListBox.ItemsSource and then specify the ItemTemplate. Check the below code.

 <Grid x:Name="LayoutRoot">
        <ListBox x:Name="TestList"  SelectionMode="Multiple">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel>
                        <CheckBox Content="Check this checkbox!"/>
                        <TextBlock Text="{Binding}"/>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
            <ListBox.Items>
                <sys:String>Bob</sys:String>
                <sys:String>Jim</sys:String>
                <sys:String>Dave</sys:String>
                <sys:String>Larry</sys:String>
                <sys:String>Tom</sys:String>
            </ListBox.Items>
        </ListBox>
    </Grid>

where sys is xmlns:sys="clr-namespace:System;assembly=mscorlib"

In this way, there are 5 ListBoxItems getting generated in the background and added to the ListBox.

You can use ItemContainerStyle instead of ItemTemplate if you want to add ListBoxItems directly to the ListBox.

Doing so, however, is only recommended when you need unique characteristics on a per item level.

If you are planning on all the items looking the same or making a dynamic list using ItemsSource, I would recommend you add strings (or another custom object) to your list and use ItemTemplate to display your items. (see Jobi Joy's answer)

Here's an example using ItemContainerStyle:

    <ListBox
        x:Name="TestList"
        SelectionMode="Multiple">

        <ListBox.ItemContainerStyle>
            <Style
                TargetType="ListBoxItem">

                <Setter
                    Property="Template">
                    <Setter.Value>
                        <ControlTemplate
                            TargetType="ListBoxItem">
                            <StackPanel>
                                <CheckBox
                                    Content="Check this checkbox!" />
                                <TextBlock
                                    Text="{TemplateBinding Content}" />
                            </StackPanel>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>

            </Style>
        </ListBox.ItemContainerStyle>

        <ListBox.Items>
            <ListBoxItem>Bob</ListBoxItem>
            <ListBoxItem>Jim</ListBoxItem>
            <ListBoxItem>Dave</ListBoxItem>
            <ListBoxItem>Larry</ListBoxItem>
            <ListBoxItem>Tom</ListBoxItem>
        </ListBox.Items>
    </ListBox>