是因为进程权限的问题，需要添加下面的代码：
BOOL EnableDebugPrivilege()
{
HANDLE hToken;
BOOL fOk=FALSE;
if(OpenProcessToken(GetCurrentProcess(),TOKEN_ADJUST_PRIVILEGES,&hToken))
{
TOKEN_PRIVILEGES tp;
tp.PrivilegeCount=1;
if(!LookupPrivilegeValue(NULL,SE_DEBUG_NAME,&tp.Privileges[0].Luid))
TRACE("Can't lookup privilege value.
");
tp.Privileges[0].Attributes=SE_PRIVILEGE_ENABLED;
if(!AdjustTokenPrivileges(hToken,FALSE,&tp,sizeof(tp),NULL,NULL))
TRACE("Can't adjust privilege value.
");
fOk=(GetLastError()==ERROR_SUCCESS);
CloseHandle(hToken);
}
return fOk;
}