iOS 9如何检测静音模式？
iOS 9如何检测静音模式？
提问于 2015-12-05 12:42:08
当AudioSessionInitialize和AudioSessionGetProperty被废弃时，我得到了错误的返回值：
CFStringRef state = nil;
UInt32 propertySize = sizeof(CFStringRef);
AudioSessionInitialize(NULL, NULL, NULL, NULL);
OSStatus status = AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);
[[AVAudioSession sharedInstance] setActive:YES error:nil];
if (status == kAudioSessionNoError) {
return CFStringGetLength(state) == 0; // YES = silent
}
return NO;从这段代码(我发现它是这里)中，无论设备实际处于什么状态，我都会得到相同的不正确结果。如何检测静音模式现在是否在设备上？
回答 1
Stack Overflow用户
发布于 2015-12-05 15:04:11
API不再可用。但是周围的工作很简单：
- 播放一个简短的音频，并检测它完成播放的时间。
- 如果它完成播放的时间比音频的实际长度短，则该设备是静音的。
Hoishing在他的博客上发布了一个助手类博客。将其用作以下用途：
self.muteChecker = [[MuteChecker alloc] initWithCompletionBlk:^(NSTimeInterval lapse, BOOL muted) {
NSLog(@"muted: %d", muted);
}];
[self.muteChecker check];这是该类的完整代码，您可以简单地将其复制到项目中：
MuteChecker.h
#import <Foundation/Foundation.h>
#import <AudioToolbox/AudioToolbox.h>
typedef void (^MuteCheckCompletionHandler)(NSTimeInterval lapse, BOOL muted);
// this class must use with a MuteChecker.caf (a 0.2 sec mute sound) in Bundle
@interface MuteChecker : NSObject
-(instancetype)initWithCompletionBlk:(MuteCheckCompletionHandler)completionBlk;
-(void)check;
@endMuteChecker.cpp
#import "MuteChecker.h"
void MuteCheckCompletionProc(SystemSoundID ssID, void* clientData);
@interface MuteChecker ()
@property (nonatomic,assign) SystemSoundID soundId;
@property (strong) MuteCheckCompletionHandler completionBlk;
@property (nonatomic, strong)NSDate *startTime;
-(void)completed;
@end
void MuteCheckCompletionProc(SystemSoundID ssID, void* clientData){
MuteChecker *obj = (__bridge MuteChecker *)clientData;
[obj completed];
}
@implementation MuteChecker
-(void)playMuteSound
{
self.startTime = [NSDate date];
AudioServicesPlaySystemSound(self.soundId);
}
-(void)completed
{
NSDate *now = [NSDate date];
NSTimeInterval t = [now timeIntervalSinceDate:self.startTime];
BOOL muted = (t > 0.1)? NO : YES;
self.completionBlk(t, muted);
}
-(void)check {
if (self.startTime == nil) {
[self playMuteSound];
} else {
NSDate *now = [NSDate date];
NSTimeInterval lastCheck = [now timeIntervalSinceDate:self.startTime];
if (lastCheck > 1) { //prevent checking interval shorter then the sound length
[self playMuteSound];
}
}
}
- (instancetype)initWithCompletionBlk:(MuteCheckCompletionHandler)completionBlk
{
self = [self init];
if (self) {
NSURL* url = [[NSBundle mainBundle] URLForResource:@"MuteChecker" withExtension:@"caf"];
if (AudioServicesCreateSystemSoundID((__bridge CFURLRef)url, &_soundId) == kAudioServicesNoError){
AudioServicesAddSystemSoundCompletion(self.soundId, CFRunLoopGetMain(), kCFRunLoopDefaultMode, MuteCheckCompletionProc,(__bridge void *)(self));
UInt32 yes = 1;
AudioServicesSetProperty(kAudioServicesPropertyIsUISound, sizeof(_soundId),&_soundId,sizeof(yes), &yes);
self.completionBlk = completionBlk;
} else {
NSLog(@"error setting up Sound ID");
}
}
return self;
}
- (void)dealloc
{
if (self.soundId != -1){
AudioServicesRemoveSystemSoundCompletion(self.soundId);
AudioServicesDisposeSystemSoundID(self.soundId);
}
}
@end重要注意事项:您还必须提供一个简短的音频MuteChecker.caf代码才能工作。你可以直接从他的博客下载一个，也可以自己生成一个。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/34105022
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