<UserControl x:Class="WPF1.UserControl1"

             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 

             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 

             mc:Ignorable="d" 

             d:DesignHeight="200" d:DesignWidth="200" Background="Blue">

    <Grid>

       <Button Content="张三" FontSize="30" Height="100" Width="100" Background="Red" Click="button1_Click"/>

    </Grid>

</UserControl>

public partial class UserControl1 : UserControl

{

    public UserControl1()

    {

        InitializeComponent();

    }

    private void button1_Click(object sender, RoutedEventArgs e)

    {

        GetWeiShu(this);

    }

    public void GetWeiShu(DependencyObject obj)

    {

        Button button = null;

        DependencyObject d;

        foreach (var c in LogicalTreeHelper.GetChildren(obj))

        {

            d = c as DependencyObject;

            if (d != null)

            {

                button = d as Button;

                if (button != null)

                {

                    MessageBox.Show("ss");

                    break;

                }

                GetWeiShu(d);//递归执行。

            }

        }

        MessageBox.Show("李四");

    }

}

<Window x:Class="WPF1.MainWindow"

        xmlns="http://schemas.microsoft.com/w