扩展WPF的TreeView，完成数据绑定和拖拽功能

扩展WPF的TreeView，完成数据绑定和拖拽功能。 WPF看了很长时间了，但一直没怎么动手实践，正好任务需要，扩展了WPF的标准TreeView控件，并作为基础控件，支持下面的功能： 数据绑定 拖拽

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;

namespace WpfApp2
{
    /// 

    /// Interaction logic for App.xaml
    /// 

    public partial class App : Application
    {
    }
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2019-04-10 08:31  WpfApp2\.vs\
     目录           0  2019-04-10 08:31  WpfApp2\.vs\WpfApp2\
     目录           0  2019-04-10 08:31  WpfApp2\.vs\WpfApp2\v15\
     文件       96256  2019-04-11 16:31  WpfApp2\.vs\WpfApp2\v15\.suo
     目录           0  2019-04-10 08:31  WpfApp2\.vs\WpfApp2\v15\Server\
     目录           0  2019-04-11 10:53  WpfApp2\.vs\WpfApp2\v15\Server\sqlite3\
     文件           0  2019-04-10 08:31  WpfApp2\.vs\WpfApp2\v15\Server\sqlite3\db.lock
     文件      712704  2019-04-11 12:56  WpfApp2\.vs\WpfApp2\v15\Server\sqlite3\storage.ide
     文件       32768  2019-04-11 13:03  WpfApp2\.vs\WpfApp2\v15\Server\sqlite3\storage.ide-shm
     文件     4120032  2019-04-11 16:25  WpfApp2\.vs\WpfApp2\v15\Server\sqlite3\storage.ide-wal
     文件        1119  2019-04-10 08:31  WpfApp2\WpfApp2.sln
     目录           0  2019-04-11 16:25  WpfApp2\WpfApp2\
     文件         189  2019-04-10 08:31  WpfApp2\WpfApp2\App.config
     文件         368  2019-04-10 08:31  WpfApp2\WpfApp2\App.xaml
     文件         340  2019-04-10 08:31  WpfApp2\WpfApp2\App.xaml.cs
     目录           0  2019-04-10 08:31  WpfApp2\WpfApp2\bin\
     目录           0  2019-04-11 11:07  WpfApp2\WpfApp2\bin\Debug\
     目录           0  2019-04-11 11:07  WpfApp2\WpfApp2\bin\Debug\de\
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\de\Microsoft.expression.Interactions.resources.dll
     文件        4096  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\de\Microsoft.expression.Prototyping.Interactivity.resources.dll
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\de\System.Windows.Interactivity.resources.dll
     目录           0  2019-04-11 11:07  WpfApp2\WpfApp2\bin\Debug\en\
     文件        7168  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\en\Microsoft.expression.Interactions.resources.dll
     文件        4608  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\en\Microsoft.expression.Prototyping.Interactivity.resources.dll
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\en\System.Windows.Interactivity.resources.dll
     目录           0  2019-04-11 11:07  WpfApp2\WpfApp2\bin\Debug\es\
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\es\Microsoft.expression.Interactions.resources.dll
     文件        4096  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\es\Microsoft.expression.Prototyping.Interactivity.resources.dll
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\es\System.Windows.Interactivity.resources.dll
     目录           0  2019-04-11 11:07  WpfApp2\WpfApp2\bin\Debug\fr\
     文件        6656  2010-05-25 18:26  WpfApp2\WpfApp2\bin\Debug\fr\Microsoft.expression.Interactions.resources.dll
............此处省略75个文件信息