iphone - AVAudioRecorder 不会在设备上录制

Question

这是我的方法:

-(void) playOrRecord:(UIButton *)sender {
    if (playBool == YES) {
        NSError *error = nil;
        NSString *filePath = [[NSBundle mainBundle] pathForResource:[NSString stringWithFormat: @"%d", [sender tag]] ofType:@"caf"];
        NSURL *fileUrl = [NSURL fileURLWithPath:filePath];
        AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:fileUrl error:&error];
        [player setNumberOfLoops:0];
        [player play];      
    }
    else if (playBool == NO) {
        if ([recorder isRecording]) {
            [recorder stop];
            [nowRecording setImage:[UIImage imageNamed:@"NormalNormal.png"] forState:UIControlStateNormal];
            [nowRecording setImage:[UIImage imageNamed:@"NormalSelected.png"] forState:UIControlStateSelected];
        }
        if (nowRecording == sender) {
        nowRecording = nil;
        return;
        }
        nowRecording = sender;
        NSError *error = nil;
        NSString *filePath = [[NSBundle mainBundle] pathForResource:[NSString stringWithFormat: @"%d", [sender tag]] ofType:@"caf"];
        NSURL *fileUrl = [NSURL fileURLWithPath:filePath];
        [sender setImage:[UIImage imageNamed:@"RecordingNormal.png"] forState:UIControlStateNormal];
        [sender setImage:[UIImage imageNamed:@"RecordingSelected.png"] forState:UIControlStateSelected];        
        recorder = [[AVAudioRecorder alloc] initWithURL:fileUrl settings:recordSettings error:&error];
        [recorder record];
    }
}

大部分内容都是不言自明的； playBool 是一个 BOOL，在播放模式下为 YES。一切都在模拟器中运行，但是，当我在设备上运行它时，[记录器记录]返回“否”。有谁知道为什么会发生这种情况吗？

Answer 1

如果您的代码中的任何位置有此设置:

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];

将其更改为:

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

设置错误的AVAudioSession类别会导致录音/播放失败。