一般的Listbox的拖拽均为其他listbox控件或是别的控件到listbox控件的拖拽，而该程序成功地实现了listbox内部的拖拽命令，并有向上，向下移动Item选项的功能。-General Listbox drag are other Listbox control or other control to the Listbox control drag and drop, and the program successfully realized the Listbox interna