如下代码所示，如何实现点击button后能取到textblock的值

Question

<ListBox x:Name="callhistory" SelectionChanged="phonenum">
                                <ListBox.ItemTemplate >
                                    <DataTemplate x:Name="ch" >
                                        <StackPanel Orientation="Horizontal">
                                            <Button  Name="btn"  Click="press" 
                                                                                            </Button>
                                            <TextBlock Name="pn" FontSize="50" Text="{Binding phonenum}"></TextBlock>
                                        </StackPanel>
                                    </DataTemplate>
                                </ListBox.ItemTemplate>
                            </ListBox>

Answer 1

如上代码所示，如何实现点击button后能取到textblock的值