audiofileopenurl在现有文件上返回-43

在我的应用程序中,有一个步骤是用户反复听到三个语音数字。

如果我让此步骤运行一段时间(对于某些未定义的值“while”),我的调试日志将显示此信息(删除了不相关的日志条目):

2010-03-01 13:44:21.283 iPhoneHearChk[1236:207] AudioFileOpenURL returned 0
 (for <file://localhost/var/mobile/Applications/3A28F975-EAD5-4A5B-AFE6-FA1C6EE95732/iPhoneHearChk.app/5b3.ima4>)
2010-03-01 13:44:35.493 iPhoneHearChk[1236:207] AudioFileOpenURL returned 0
 (for <file://localhost/var/mobile/Applications/3A28F975-EAD5-4A5B-AFE6-FA1C6EE95732/iPhoneHearChk.app/5b3.ima4>)
2010-03-01 13:45:17.916 iPhoneHearChk[1236:207] AudioFileOpenURL returned 0
 (for <file://localhost/var/mobile/Applications/3A28F975-EAD5-4A5B-AFE6-FA1C6EE95732/iPhoneHearChk.app/5b3.ima4>)
2010-03-01 13:47:00.408 iPhoneHearChk[1236:207] AudioFileOpenURL returned -43
 (for <file://localhost/var/mobile/Applications/3A28F975-EAD5-4A5B-AFE6-FA1C6EE95732/iPhoneHearChk.app/5b3.ima4>)

据我所读,macerrors.h将-43定义为fnerr,找不到文件。但很明显文件 做 存在,因为我以前成功打开过它。给出了什么?

如何打开文件:

NSString *soundFilePath = [[NSBundle mainBundle] pathForResource: name ofType: type];
if (!soundFilePath) { NSLog(@"No path found for sound file %@.%@", name, type); }
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath: soundFilePath];
rc = AudioFileOpenURL((CFURLRef) fileURL, kAudioFileReadPermission, 0, &file);

其中file是audiofileid instvar,name和type是nsstring*参数。