最好先调用GetCurrentProcess,虽然它返回的句柄就是-1
MSDN里有如下内容:
A pseudo handle is a special constant, currently (HANDLE)-1, that is interpreted as the current process handle. For compatibility with future operating systems, it is best to call GetCurrentProcess instead of hard-coding this constant value. The calling process can use a pseudo handle to specify its own process whenever a process handle is required. Pseudo handles are not inherited by child processes.