如果datacontext是T类型的对象，如何将样式应用于treeviewitem

Question

Is there a way to do this, or do I have to create an IsSelectedProperty on the ViewModel and Bind to that instead?

I would like to be able to do something like Source={Binding RelativeAncestor ListViewItem}

but instead there is only this property sourcename which I can use to set triggers based off of the items in the datatemplate if I name them using x:Name

                <HierarchicalDataTemplate.Triggers>
                  <Trigger SourceName="" Property="IsSelected" Value="True">
                    <Setter TargetName="bdr" Property="Foreground" Value="White"/>
                    <Setter TargetName="bdr" Property="Foreground" Value="Red"/>
                  </Trigger>
                </HierarchicalDataTemplate.Triggers>

Looking back, I realized that yesterday I made a very confusing post. Also, considering how hard I find it to even interpret people's comments to my questions, I should probably give more detail.

I know that in wpf you can set triggers based on the control by setting a style for the target control type.

In addition you also have data triggers that can trigger off of properties in the datacontext. What I was hoping was that there was a way to use triggers, or datatriggers to set a property when the datacontext is an object of a specific type.

is this possible? If not, I will just accept the provided answer as applicable in my situation, but since this will require me to add a property to my viewmodel, it seemed reasonable to check if there was a way to just check item type rather than having to check the actual property.

Answer 1

I would suggest that you bind the IsSelected property in your view model, but that's just me.

I'm not sure how complex your HierarchicalDataTemplate is, or if some items need to have their Foreground changed, and some don't; but I'm going to assume you want to update the item that is selected throughout the entire TreeView (if that's what this is for).

If that is the case, just add DataTrigger s to the Style of the TreeViewItem :

<Style TargetType="TreeViewItem">
    <Setter Property="IsSelected"
            Value="{Binding IsSelected, Mode=TwoWay}" />
    <Style.Triggers>
        <DataTrigger Binding="{Binding IsSelected}" Value="True">
            <Setter Property="Foreground"
                    Value="Red" />
        </DataTrigger>
        <DataTrigger Binding="{Binding IsSelected}"
                     Value="False">
            <Setter Property="Foreground"
                    Value="Black" />
        </DataTrigger>
    </Style.Triggers>
</Style>

Note that you don't need to bind the IsSelected parameter if you don't want to, its just there because it's in my code.