title: cannot set tooltip in style
body: <p>I searched and find out I can't set the tooltip in setter.value directly (in a style.xaml file). However I can use static resource to set the tooltip.</p>
  
  <p>My question is, since I need to supply dynamic text for the tooltip, I can't use static resource. How should I do that?</p>
  
  <p>here is my example.</p>
  
  <pre><code>    &lt;Style x:Key="ErrorStyleRadius" TargetType="{x:Type FrameworkElement}"&gt;
      &lt;Style.Triggers&gt;
          &lt;MultiDataTrigger&gt;
              &lt;MultiDataTrigger.Conditions&gt;
                  &lt;Condition Binding="{Binding (Validation.HasError), RelativeSource={RelativeSource Mode=Self}}" Value="True"/&gt;
                  &lt;Condition Binding="{Binding (Validation.Errors), RelativeSource={RelativeSource Mode=Self}, Converter={StaticResource IsError}}" Value="True"/&gt;
              &lt;/MultiDataTrigger.Conditions&gt;
              &lt;MultiDataTrigger.Setters&gt;
                  &lt;Setter Property="ToolTip"&gt;
                      &lt;Setter.Value&gt;
                          &lt;ToolTip&gt;
                              &lt;Label Content="{Binding somePropertyHere}"/&gt;
                          &lt;/ToolTip&gt;
                      &lt;/Setter.Value&gt;
                  &lt;/Setter&gt;
                  &lt;Setter Property="Validation.ErrorTemplate" Value="{StaticResource ErrorControlTemplateRadiusError}"/&gt;
              &lt;/MultiDataTrigger.Setters&gt;
          &lt;/MultiDataTrigger&gt;
  
          &lt;MultiDataTrigger&gt;
              &lt;MultiDataTrigger.Conditions&gt;
                  &lt;Condition Binding="{Binding (Validation.HasError), RelativeSource={RelativeSource Mode=Self}}" Value="True"/&gt;
                  &lt;Condition Binding="{Binding (Validation.Errors), RelativeSource={RelativeSource Mode=Self}, Converter={StaticResource IsWarning}}" Value="True"/&gt;
              &lt;/MultiDataTrigger.Conditions&gt;
              &lt;MultiDataTrigger.Setters&gt;
                  &lt;Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors), Converter={StaticResource ValMsg}}"/&gt;
                  &lt;Setter Property="Validation.ErrorTemplate" Value="{StaticResource ErrorControlTemplateRadiusWarning}"/&gt;
              &lt;/MultiDataTrigger.Setters&gt;
          &lt;/MultiDataTrigger&gt;
      &lt;/Style.Triggers&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>for usage, i can use as </p>
  
  <pre><code>&lt;textbox style={staticresource ErrorStyleRadius} text={bind name, validationOnDataError=true}/&gt;
  </code></pre>