实现在CListCtrl中动态创建下拉列表框、文件框，输入完成完自动销毁. 运行测试程序后,双击列表框能看见实现效果,,Achieve in CListCtrl dynamically create a drop-down list box, file box, enter the complete End of self-destruct. Run test procedures, double-click the list box to see the achievement of resu