Question

I have a datagrid and in DataGridTemplateColumn, I have a togglebutton which when checked, it opens a Popup for comments with the help of ElementName binding.

<WpfToolkit:DataGridTemplateColumn>
                            <WpfToolkit:DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <Grid >
                                        <StackPanel Orientation="Vertical">
                                            <ToggleButton Content="C" Name="toggleButon" VerticalAlignment="Center" Background="Transparent"></ToggleButton>

                                        <Popup  Height="Auto" Width="300" IsOpen="{Binding ElementName=toggleButon,Path=IsChecked}" StaysOpen="True" AllowsTransparency="True">
                                            <Border BorderThickness="2" Background="LightGray">
                                                <StackPanel Margin="20"  Orientation="Vertical">
                                                        <TextBlock Text="Bloomberg Run Text Comment" Foreground="Black"></TextBlock>
                                                    <TextBox Text="check"/>

                                                </StackPanel>
                                            </Border>
                                        </Popup>
                                        </StackPanel>
                                    </Grid>
                                </DataTemplate>
                            </WpfToolkit:DataGridTemplateColumn.CellTemplate>
                        </WpfToolkit:DataGridTemplateColumn>

It works as expected. But I am curious to know how the elementName binding is working at rowlevel because elementname of ToggleButton would be same for each row as I understand. So how the toggle button opens the popup window only within its scope and not any other popup window in any other row.

Answer 1

That is because the name should be unique within a given XAML namespace.
in WPF, templates have unique XAML namespace within root namespace.

http://msdn.microsoft.com/en-us/library/ms746659.aspx#Namescopes_in_Styles_and_Templates