Hi: I'm confused by a problem when i modify a test application "alsa-lib-1.0.13/test/control.c". I wanna use the structure "snd_ctl_elem_value_t",but when i write like this: snd_ctl_elem_value_t aaa; there will be an error: storage size of 'aaa' isn't known while snd_ctl_elem_value_t *aaa; makes no errors. But i can't change it directly such as: aaa->id=test_id ; //test_id is defined before cause it will bring an error: dereferencing pointer to incomplete type I think i should use the function like "snd_ctl_elem_info_set_id",but i just want to know why,i don't think it disobeys the C syntax.Is there something different in the ALSA making procedure?or Makefile?

haoshun 2008-04-03