test

samples/ControlCatalog/Pages/TextBoxPage.xaml

@@ -6,9 +6,9 @@
       <StackPanel.Styles>
         <Style Selector="TextBox">
           <Setter Property="InnerRightContent">
-            <DataTemplate>
+            <ControlTemplate>
               <Button Content="Clear" />
-            </DataTemplate>
+            </ControlTemplate>
           </Setter>
 
         </Style>

src/Avalonia.Themes.Fluent/TextBox.xaml

@@ -86,7 +86,7 @@
                                     HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                     VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/> 
                       </Panel>
-                      <ContentPresenter Grid.Column="0" Grid.ColumnSpan="1" Content="{TemplateBinding InnerLeftContent}"/>
+                      <ContentPresenter Grid.Column="0" Grid.ColumnSpan="1" Content="{TemplateBinding InnerRightContent}"/>
                     </Grid>
                   </ScrollViewer>
                 </DataValidationErrors>