如何为 TreeView 中的 ToolTip 提供 MaxWidth（或自定义样式）

Question

I have a ResourceDictionary that has a TreeView.

Here, I am trying to give a MaxWidth to my MainItemStyle's tooltip (as my bound text 'TxtDescription' is very long), and for doing that i tried to give a template to this tooltip but it got applied to the base TreeViewItem instead.

Additionally, I am trying to set tooltip to the TreeView header items only, but i think that is not possible with a TreeView's structure.

My code is like this:

<ResourceDictionary>
<TreeView ItemsSource="{Binding MainItems, UpdateSourceTrigger=PropertyChanged}"
          ItemContainerStyle="{StaticResource MainItemStyle}">
        <TreeView.ItemTemplate>
          <HierarchicalDataTemplate ItemsSource="{Binding ChildList}" ItemTemplate="{StaticResource childTemplate}" ItemContainerStyle="{StaticResource ChildItemStyle}">           
          </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>        
</TreeView>

<Style x:Key="basicStyle" TargetType="TreeViewItem" BasedOn="{StaticResource {x:Type TreeViewItem}}">
    <Setter Property="Margin" Value="0"/>
    <Setter Property="Padding" Value="2,2"/>    
    <Setter Property="SnapsToDevicePixels" Value="True"/>    
  </Style>

  <Style x:Key="ChildItemStyle" TargetType="TreeViewItem" BasedOn="{StaticResource basicStyle}">    
  </Style>

  <Style x:Key="MainItemStyle" TargetType="TreeViewItem" BasedOn="{StaticResource basicStyle}">
    <Setter Property="ToolTip" Value="{Binding TxtDescription}"/>    
  </Style>
</ResourceDictionary>

Can anyone please provide me any solution for the tooltip's MaxWidth (or styling) here. Thanks a ton.

Answer 1

Just assign a ToolTip control to the TreeViewItem.ToolTip property and customize it:

<Style x:Key="MainItemStyle" TargetType="TreeViewItem" BasedOn="{StaticResource basicStyle}">
  <Setter Property="ToolTip">
    <Setter.Value>
      <ToolTip Content="{Binding TxtDescription}" 
               MaxWidth="500" />    
    </Setter.Value>
  </Setter>
</Style>