How to specify a ToolTip for a control in a Style from XAML?

Question

I'm using a the WPF datagrid from the Microsoft CodePlex project. I have a custom control that I want to databind to a field from the row of the datagrid. I can't for the life of me figure out how to specify a tooltip on a datagrid row.

The closest I've come is to use a RowStyle with a Setter to set the tooltip, but this only seems to work for text. When I try to put a ControlTempalte in as the Value for the ToolTip, it displays the result of calling ToString on the ControlTemplate type.

I think I need to set the "Template" property of the ToolTip, but I can't seem to figure out how to do that...

  <dg:DataGrid Name="dgResults" AutoGenerateColumns="True">

            <dg:DataGrid.RowStyle >


            <Style TargetType="{x:Type dg:DataGridRow}">

                <Setter Property="ToolTip"  >
                    <Setter.Value>

                        <ControlTemplate TargetType="{x:Type ToolTip}">
                           <StackPanel>
                                 <TextBlock>txt1</TextBlock><TextBlock>txt2</TextBlock>
                           </StackPanel>
                        </ControlTemplate>


                    </Setter.Value>
                </Setter>
            </Style>

        </dg:DataGrid.RowStyle>

  </dg:DataGrid>

Answer 1

There's no need for the ControlTemplate. If you want the StackPanel in the ToolTip, just set it as:

<Setter Property="ToolTip">
    <Setter.Value>
     <StackPanel>
      <TextBlock>txt1</TextBlock><TextBlock>txt2</TextBlock>
     </StackPanel>
    </Setter.Value>
</Setter>

HTH, Kent

Answer 2

Not sure you can do it through XAML.

A easier way might be to just handle the LoadingRow event. In xaml have something like:

<dg:DataGrid Name="dgResults" AutoGenerateColumns="True" 
             LoadingRow="dgResults_LoadingRow" 
             ItemsSource="{Binding ListOfStrings}" />

Then in code behind

void dgResults_LoadingRow(object sender, DataGridRowEventArgs e)
{
    DataGridRow row = e.Row;
    row.ToolTip = row.DataContext as string;
}

Obviously you will have to change the code depending on how you are populating the data in the datagrid. This is also untested =)

Answer 3

Figured it out... took me about 6 hours...

For some reason, I can't set the value directly using Value.Setter. If I define the content for the tooltip as a static resource though, and then set it in the Style property of the DataGrid.RowStyle it works.

So, the datagrid row style looks like:

            <Style TargetType="{x:Type dg:DataGridRow}">

                <Setter Property="ToolTip" Value="{StaticResource resKWIC}">
                </Setter>                 
            </Style>

        </dg:DataGrid.RowStyle>

And the resource is

<Window.Resources>
    <StackPanel x:Key="resKWIC">
        <TextBlock>f1</TextBlock>
        <TextBlock>f2></TextBlock>
    </StackPanel>
</Window.Resources>

Thanks!

Answer 4

You can use a IMultiValueConverter like the example below:

http://codefornothing.wordpress.com/2009/01/25/the-wpf-datagrid-and-me/

I based my implementation on that example and substituted the BackgroundProperty with the ToolTipProperty.

Answer 5

The key is to use the Property ToolTipService.ToolTip, instead of ToolTip - like this:

<Setter Property="ToolTipService.ToolTip" Value="My Tooltip"/>