Add text to a ToolTip when hovering over a cell that has a slash in it in WPF

Question

I have add a tool tip to my WPF datagrid to show data when the mouse is hovered over. I was wondering if it would be possible to also add text to that ToolTip when only hovering over data that has a slash in it.

EX of data would be: 2.34/25 and 22/2

EX of ToolTip when hovering over data with a slash would be: TEST MSG 2.34/25

</UserControl.Resources>
        <Style x:Key="DataGridCellStyle" TargetType="{x:Type DataGridCell}" >
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="LightBlue"/>
                    <Setter Property="Foreground" Value="Black"/>
                </Trigger>
            </Style.Triggers>
              <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Mode=Self}, Path=Content.Text}" />
            <Setter Property="Height" Value="25" />
        </Style>
</UserControl.Resources>

Answer 1

You can use two converters and data trigger.

First converter to check if text contains slash:

public class SlashTextConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value != null && value.ToString().Contains("/"))
            return true;
        else
            return false;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Second converter to format custom message:

public class CustomToolTipMessage : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return string.Format("TEST MSG {0}", value);
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

And here is style with DataTrigger:

<Window.Resources>
    <local:SlashTextConverter x:Key="slashConverter" />
    <local:CustomToolTipMessage x:Key="customToolTipConverter" />

    <Style TargetType="{x:Type DataGridCell}">
        <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Mode=Self}, Path=Content.Text}" />

        <Style.Triggers>
            <Trigger Property="IsSelected" Value="True">
                <Setter Property="Background" Value="LightBlue"/>
                <Setter Property="Foreground" Value="Black"/>                    
            </Trigger>

            <DataTrigger Binding="{Binding Path=Content.Text, RelativeSource={RelativeSource Mode=Self}, Converter={StaticResource slashConverter}}" Value="True">
                <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Mode=Self}, Path=Content.Text, Converter={StaticResource customToolTipConverter}}" />                                           
            </DataTrigger>     
        </Style.Triggers>                                   
    </Style>
</Window.Resources>