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wpflistboxexpander

How do I anchor an expander to right side of a ListBox?

The XAML code below works fine except I want the expander button to be between the listbox and the grid. If I set the ExpandDirection="Left" the button is between the listbox and the grid but the direction indicator on the button is confusing to users - it point to the right when expanded and it points to the left when it is not expanded. I want the direction indicator to work the way it does when ExpandDirection="Right" but I want the functionality of ExpandDirection="Left".

<DockPanel>
    <Expander ExpandDirection="Right">
        <ListBox>
            <ListBoxItem>Item One</ListBoxItem>
            <ListBoxItem>Item Two</ListBoxItem>
            <ListBoxItem>Item Three</ListBoxItem>
            <ListBoxItem>Item Four</ListBoxItem>
            <ListBoxItem>Item Five</ListBoxItem>
        </ListBox>
    </Expander>
        <Grid Background="AliceBlue">
          <TextBlock >
            Other Content
          </TextBlock>
        </Grid>
</DockPanel>
Solution

  • Use Expression Blend, edit a copy of the current template for the Expander, go to XAML for the template, rename "ExpanderLeftHeaderStyle" to "ExpanderRightHeaderStyle" and "ExpanderRightHeaderStyle" to "ExpanderLeftHeaderStyle".