How to create ToolTip for DataGridColumnHeader in WPF?

Question

I have found how to create ToolTip for DataGridColumnHeader in WPF (and make sure that the Header is wrapped).

<Style x:Key="StartingTabToolTipHeaderStyle" TargetType="DataGridColumnHeader">
   <Setter Property="ToolTip" Value="{x:Static r:Resource.StartingTabToolTip}"/>
   <Setter Property="ContentTemplate">
      <Setter.Value>
         <DataTemplate>
            <TextBlock TextWrapping="Wrap" Text="{Binding}"/>
         </DataTemplate>
      </Setter.Value>
   </Setter>
</Style>

I can use this style in this way:

<DataGridComboBoxColumn Header="{x:Static r:Resource.StartingTab}" SelectedItemBinding="{Binding StartingTab}" 
                        HeaderStyle="{StaticResource StartingTabToolTipHeaderStyle}">

This solution is not nice because I need to create a separate style for each header because the tooltip is hardwired in the style. I would like a general style which can be used in this way:

<DataGridComboBoxColumn Header="{x:Static r:Resource.StartingTab}" SelectedItemBinding="{Binding StartingTab}" 
                        MyToolTip="{x:Static r:Resource.StartingTabToolTip}">

Any idea how to do it? May be with attached property?

Answer 1

You can set the ToolTipService.ToolTip attached property on each column and bind your values to it, because it is not used on columns.

<DataGridComboBoxColumn Header="{x:Static r:Resource.StartingTab}"
                        SelectedItemBinding="{Binding StartingTab}" 
                        HeaderStyle="{StaticResource StartingTabToolTipHeaderStyle}"
                        ToolTipService.ToolTip="{x:Static r:Resource.StartingTabToolTip}">

Then you can bind this text on the column in your header style using a RelativeSource binding.

<Style x:Key="StartingTabToolTipHeaderStyle" TargetType="{x:Type DataGridColumnHeader}">
   <Setter Property="ToolTip" Value="{Binding Column.(ToolTipService.ToolTip), RelativeSource={RelativeSource Self}}"/>
   <Setter Property="ContentTemplate">
      <Setter.Value>
         <DataTemplate>
            <TextBlock TextWrapping="Wrap" Text="{Binding}"/>
         </DataTemplate>
      </Setter.Value>
   </Setter>
</Style>

Now you only have a single style. If you want to avoid setting the style on each column, make it an implicit style by omitting the x:Key. Then it will be applied to all matching types in scope.

<Style TargetType="{x:Type DataGridColumnHeader}">