面对两个错误.
这个代码在iOS 4和5中工作,但更新到6后,它不工作(
从iOS 6开始,应用程序需要在其UIBackgroundModes中具有音频密钥才能使用CoreMIDI的MIDISourceCreate和MIDIDestinationCreate函数.没有密钥集,这些功能将返回kMIDINotPermitted(-10844).
2012-09-23 03：40：04.773 MidiStudio [1017：907]错误(创建MIDI虚拟源)：-10844：错误域= NSMachErrorDomain代码= -10844“操作无法完成(Mach error -10844. )”
2012-09-23 03：40：04.777 MidiStudio [1017：907]错误(创建MIDI虚拟目的地)：-10844：错误域= NSMachErrorDomain代码= -10844“操作无法完成(Mach error -10844. )”
这里是’source’的代码：
-(void)setVirtualSourceEnabled:(BOOL)virtualSourceEnabled {
if ( virtualSourceEnabled == self.virtualSourceEnabled ) return;
if ( virtualSourceEnabled ) {
NSString *name = virtualEndpointName ? virtualEndpointName : [[[NSBundle mainBundle] infoDictionary] valueForKey:(NSString*)kcfBundleNameKey];
OSStatus s = MIDISourceCreate(client,(CFStringRef)name,&virtualSourceEndpoint);
NSLogError(s,@"Create MIDI virtual source");
if ( s != noErr ) return;
virtualSourceDestination = [[PGMidiVirtualSourceDestination alloc] initWithMidi:self endpoint:virtualSourceEndpoint];
[delegate midi:self destinationAdded:virtualSourceDestination];
[[NSNotificationCenter defaultCenter] postNotificationName:PGMidiDestinationAddedNotification
object:self
userInfo:[NSDictionary dictionaryWithObject:virtualSourceDestination
forKey:PGMidiEndpointKey]];
} else {
[delegate midi:self destinationRemoved:virtualSourceDestination];
[[NSNotificationCenter defaultCenter] postNotificationName:PGMidiDestinationRemovedNotification
object:self
userInfo:[NSDictionary dictionaryWithObject:virtualSourceDestination
forKey:PGMidiEndpointKey]];
[virtualSourceDestination release]; virtualSourceDestination = nil;
OSStatus s = MIDIEndpointDispose(virtualSourceEndpoint);
NSLogError(s,@"Dispose MIDI virtual source");
virtualSourceEndpoint = NULL;
}
}
解决方法
[把我的笔记放在库尔特的优秀答案上.]
首先,这一切都在文档中被称为“iOS 6.0发行说明”.那条线说：
Beginning in iOS 6,apps need to have the audio key in their
UIBackgroundModes in order to use CoreMIDI’s MIDISourceCreate and
MIDIDestinationCreate functions. Without the key set,these functions
will return kMIDINotPermitted (-10844).
所以你唯一需要做的(再次,只是指出Kurt回答)在每个目标的主张是这样的：
<key>UIBackgroundModes</key>
<array>
<string>audio</string>
</array>
