ios  如何判断设备处于静音模式

-(

BOOL

)silenced

{

#if
TARGET_IPHONE_SIMULATOR

//
return NO in simulator. Code causes crashes for some
reason.

return

NO

;

#endif

CFStringRef

state;

UInt32

propertySize = sizeof(CFStringRef);

AudioSessionInitialize(

NULL

,

NULL

,

NULL

,

NULL

);

AudioSessionGetProperty(kAudioSessionProperty_AudioRoute,
&propertySize;, &state;);

if

(CFStringGetLength(state)
>

0

)

return

NO

;

else

return

YES

;

}