wpf 查找Control Template内部控件

        private void Button1_Click(object sender, RoutedEventArgs e)
        {
            Button b = (Button)sender;
            int index = DataGrid1.SelectedIndex;
            object ww = DataGrid1.SelectedItem;

            StackPanel sp = b.Parent as StackPanel;
            Label tb = sp.FindName("Label1") as Label;


        }

                xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
            xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
            xmlns:local="clr-namespace:WpfApp5"
            xmlns:arr="clr-namespace:System.Collections;assembly=mscorlib"
            xmlns:sys="clr-namespace:System;assembly=mscorlib"
            mc:Ignorable="d"
            Title="MainWindow" Height="450" Width="800">
       
           
               
                   
                   
                   
               
               
           
       
     
     
       
           
           
       
   

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Data;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;
    using System.Windows.Navigation;
    using System.Windows.Shapes;
     
    namespace WpfApp5
    {
        ///

        /// MainWindow.xaml 的交互逻辑
        ///

        public partial class MainWindow : Window
        {
            public MainWindow()
            {
                InitializeComponent();
            }
     
            private void Btn_Click(object sender, RoutedEventArgs e)
            {
                TextBox tb = this.uc.Template.FindName("txt1", this.uc) as TextBox;
                tb.Text = "Hello,wpf";
                StackPanel sp = tb.Parent as StackPanel;
                (sp.Children[1] as TextBox).Text = "Hello control template";
                (sp.Children[2] as TextBox).Text = "I can find you";
     
            }
        }
    }