如何实现三态树的源代码，三态树就是3个状态：选择，非选，灰选。代码是VC写的。-three states how to achieve the source code tree, the tree is three states three things : choice, non-elected, gray elections. VC code is written.

此程序是利用VC++写的控件程序，主要用于上拉机和下位机的通信……并带有控制功能。-This program is written by VC++ control program, mainly for the pull-up machine and machine communication ... and with a control function.

3.VC如何使用树形控件？3.如何使用树形控件？-3 How to use tree controls?