这个属性是什么意思呀
<StackPanel x:Name="LayoutRoot" Background="White"> <StackPanel Orientation="Horizontal"> <TextBlock Name="lbl_FirstName">First name</TextBlock> <TextBox AutomationProperties.LabeledBy="{Binding ElementName=lbl_FirstName}" Name="tbFirstName" Width="100"/> </StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock Name="lbl_LastName">Last name</TextBlock> <TextBox AutomationProperties.LabeledBy="{Binding ElementName=lbl_LastName}" Name="tbLastName" Width="100"/> </StackPanel> </StackPanel>