Operations that change non-concurrent collections must have exclusive access.

Operations that change non-concurrent collections must have exclusive access. A concurrent update was performed on this collection and corrupted its state. The collection's state is no longer correct.

调用后台API提示500错误，接口返回信息如下。

原因是：

Dictionary被多个线程同时所修改导致的所措。

解决办法：

把程序的写法改了下。