c# – 从列表框拖放到文本框

我有一个列表框和文本框,我想将文本从列表框复制到文本框.

我在WPF中的代码如下：

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="465" Width="681">
<Grid>
    <ListBox x:Name="listbox1" HorizontalAlignment="Left" Height="405" Margin="10,10,0" VerticalAlignment="Top" Width="208" MouseDown="listbox1_MouseDown">
        <ListBoxItem Content="Gordon"/>
        <ListBoxItem Content="Nico"/>
    </ListBox>
    <TextBox x:Name="textbox1" HorizontalAlignment="Left" Height="405" Margin="289,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="364" SpellCheck.IsEnabled="True" Cursor="IBeam" AcceptsReturn="True" AllowDrop="True" DragEnter="textbox1_DragEnter"/>

</Grid>
</Window>

我在C#中的代码如下所示,这就是我被困的地方：

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 WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void listbox1_MouseDown(object sender,MouseButtonEventArgs e)
    {
        DragDrop.DoDragDrop(listbox1,listbox1.SelectedItem.ToString(),DragDropEffects.Copy);
    }

    private void textbox1_DragEnter(object sender,DragEventArgs e)
    {
        e.Effects = DragDropEffects.Copy;
    }

    private void textbox1_PreviewDragOver(object sender,DragEventArgs e)
    {
        e.Handled = true;
    }

}
}

提前致谢.