从暂停模式唤醒应用程式后,声音根本就不会播放.
当应用程序处于前台时,会在didReceiveRemoteNotification：方法被调用后立即播放声音.
当从挂起的模式唤醒应用程序时,当接收到ReemiveRemoteNotification：方法时,会立即播放声音的恰当方式是什么？
这是一些代码(语音管理器类)：
-(void)textToSpeechWithMessage:(Nsstring*)message andLanguageCode:(Nsstring*)languageCode{
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
NSError *error = nil;
DLog(@"Activating audio session");
if (![audioSession setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker | AVAudioSessionCategoryOptionMixWithOthers error:&error]) {
DLog(@"Unable to set audio session category: %@",error);
}
BOOL result = [audioSession setActive:YES error:&error];
if (!result) {
DLog(@"Error activating audio session: %@",error);
}else{
AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:message];
[utterance setRate:0.5f];
[utterance setVolume:0.8f];
utterance.voice = [AVSpeechSynthesisVoice voiceWithLanguage:languageCode];
[self.synthesizer speakUtterance:utterance];
}
}
-(void)textToSpeechWithMessage:(Nsstring*)message{
[self textToSpeechWithMessage:message andLanguageCode:[[NSLocale preferredLanguages] objectAtIndex:0]];
}
后来在AppDelegate中：
[[MCSpeechManager sharedInstance] textToSpeechWithMessage:messageText];
我启用了功能 – 背景模式部分中的音频,AirPlay和画中画选项.
编辑：
也许我应该开始一个后台任务并运行到期处理程序,如果需要的话？我想这可能有效,但也想听听解决这种情况的常见方式.
此外,当我在后台收到一个通知时,我得到下一个错误：
Error activating audio session: Error Domain=NSOsstatusErrorDomain
Code=561015905 “(null)”
代码561015905适用于：
AVAudioSessionErrorCodeCannotStartPlaying = ‘!pla’,/* 0x21706C61,
561015905
它被描述为：
This error type can occur if the app’s information property list does
not permit audio use,or if the app is in the background and using a
category which does not allow background audio.
但是我收到与其他类别相同的错误(AVAudioSessionCategoryAmbient和AVAudioSessionCategorySoloAmbient)
解决方法
>您是否针对最新的SDK进行构建/测试/运行？ iOS X中的通知机制有重大变化
>我必须假设对didReceiveRemoteNotification的调用必须发生在响应于所述通知的用户操作,例如点击通知消息.
>没有必要设置任何背景模式保存应用程序下载内容以响应推送通知.
如果上述所有陈述都是真实的,那么现在的答案将集中在通知到达时会发生什么.
>设备接收通知
>用户点击消息
>应用程式启动
> didReceiveRemoteNotification被调用
在步骤4,textToSpeechWithMessage按预期工作：
func application(_ application: UIApplication,didReceiveRemoteNotification
userInfo: [AnyHashable : Any],fetchCompletionHandler completionHandler:
@escaping (UIBackgroundFetchResult) -> Void) {
textToSpeechWithMessage(message: "Speak up","en-US")
}
为了简单起见,我使用OneSignal连接通知：
import Onesignal
...
_ = Onesignal.init(launchOptions: launchOptions,appId: "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")
// or
_ = Onesignal.init(launchOptions: launchOptions,appId: "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")
{
(s:String?,t:[AnyHashable : Any]?,u:Bool) in
self.textToSpeechWithMessage(message: "OneDignal","en-US")
}
textToSpeechWithMessage大部分是不变的,这里是Swift 3的完整性：
import AVFoundation
...
let synthesizer = AVSpeechSynthesizer()
func textToSpeechWithMessage(message:String,_ languageCode:String)
{
let audioSession = AVAudioSession.sharedInstance()
print("Activating audio session")
do {
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord,with: [AVAudioSessionCategoryOptions.defaultToSpeaker,AVAudioSessionCategoryOptions.mixWithOthers]
)
try audioSession.setActive(true)
let utterance = AVSpeechUtterance(string:message)
utterance.rate = 0.5
utterance.volume = 0.8
utterance.voice = AVSpeechSynthesisVoice(language: languageCode)
self.synthesizer.speak(utterance)
} catch {
print("Unable to set audio session category: %@",error);
}
}