在具有多行的DataTemplate中查找TextBox的内容

I have this code:

我有这个代码：

<StackPanel>
<ItemsControl ItemsSource="{Binding Position}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="2*" />
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="80" />
                </Grid.ColumnDefinitions>
                <TextBox Grid.Column="0" Text="{Binding Name}" Margin="5" />
                <TextBox Grid.Column="3" Text="{Binding ID}" Margin="5" />
                <Button Grid.Column="4" Content="X" Click="Delete" />
            </Grid>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>
<StackPanel>
<Ite