用法举例：从数据表中name字段写入VALComboBox的items,id字段写入VALComboBox的values,当从VALComboBox选择一个选项后，就可以从value属性获得相应的ID值，或者写value的值为某ID值，VALComboBox将定位在相应的选项上；unit VALComboBox;interfaceuses SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls, Forms, Menus, Dialogs, StdCtrls;type TValComboBox = class(TC