转自：http://blog.csdn.net/wusuopubupt/article/details/18408227
错误原因：
The reason for this warning is that const in c doesn't mean constant. It means "read only". So the value is stored at a memory address and could potentially be changed by machine code.
在c里静态数组（固定长度的数组，即LISTEN_NUM位置是常数）是允许的，而动态数组（譬如给数组的长度是用变量来表示的）不能写成 UserProfile users[LISTEN_NUM];形式的，只能自行分配内存。