IOS AVAudioSessionModeMeasurement error

Question

Greeting. I am working on the app (IOS 7) that perform some audio management and want to disable all audio preprocessing. When I do

NSError *err;
    [audioSession setCategory:AVAudioSessionCategoryRecord error:&err];
    [audioSession setCategory:AVAudioSessionModeMeasurement error:&err];

    if (err) {
        NSLog(@"Audio Session category %@ %ld %@", [err domain], (long)[err code], [[err userInfo] description]);
    }

this piece of code returns

2014-04-08 00:39:12.573 okolly[2365:60b] 00:39:12.572 ERROR:     [0x3b83f18c] AVAudioSessionUtilities.mm:96: getUInt32: -- Category Value Converter failed
2014-04-08 00:39:12.575 okolly[2365:60b] Audio Session category NSOSStatusErrorDomain -50 {
}

both on simulator and on device. If I comment

[audioSession setCategory:AVAudioSessionModeMeasurement error:&err]; 

app works as expected.

What am I doing wrong? Thank you for help.

Answer 1

与setMode：中一样，AVAudioSessionModeMeasurement不是AVAudioSession类别属性，而是模式属性。