c# wpf - cannot set both DisplayMemberPath and ItemTemplate

c#, listbox, listboxitem, wpf

Solution

`DisplayMemberPath` is, in effect, a template for a single property, shown in a `TextBlock`. If you set:

<ListBox x:Name="lstToys" Style="{DynamicResource ListBoxStyle1}"  
         ItemsSource="{Binding Strings}" DisplayMemberPath="Toys">
</ListBox>

It is equivalent to:

<ListBox x:Name="lstToys" Style="{DynamicResource ListBoxStyle1}"  
         ItemsSource="{Binding Strings}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Toys}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

You can simply remove the `DisplayMemberPath` path and use the value in your `DataTemplate`'s `Binding`:

<ListBox x:Name="lstToys" Style="{DynamicResource ListBoxStyle1}"  
         ItemsSource="{Binding Strings}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Toys}" ToolTip="Here is a tooltip!"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

Edit

If you want to set a `ToolTip` but keep the `DisplayMemberPath`, you can do it at the `ItemContainerStyle`:

<ListBox x:Name="lstToys" Style="{DynamicResource ListBoxStyle1}"  
         ItemsSource="{Binding Strings}" DisplayMemberPath="Toys">
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="ToolTip" Value="Here's a tooltip!"/>
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

I'd advise against it. Remember that use `DisplayMemberPath` stops you from any complex binding in your data template.

Problem

I want to add tooltip in listboxItem but it starts problem when there is `DisplayMemberPath`. Error message said: cannot set both DisplayMemberPath and ItemTemplate. When I removed `DisplayMemberPath`, tooltip in each list item is working. But i dont want to remove `DisplayMememberPath` because I need it. How to solve this problem? ``` <ListBox x:Name="lstToys" Style="{DynamicResource ListBoxStyle1}" ItemsSource="{Binding Strings}" DisplayMemberPath="Toys" MouseDoubleClick="lstToys_MouseDoubleClick"> <ListBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding}" ToolTip="Here is a tooltip"/> </DataTemplate> </ListBox.ItemTemplate> </ListBox> ```

Original source