Swift TTS，无音频输出

我尝试在我的应用程序 TTS 中集成，但如果单击按钮，则没有音频输出。这是按钮代码：

struct VocabDetailView: View {
//...
    var body: some View {
//...
        HStack{
            Button("Play") {
                readOut(text: "test")
            }
        }
    }
}
//The code from readOut is:

func readOut(text: String) {
    let utterance = AVSpeechUtterance(string: text)
    utterance.voice = AVSpeechSynthesisVoice(language: "en-US")

    let synth = AVSpeechSynthesizer()
    synth.speak(utterance)
}

每次我单击按钮时，Xcode 的输出字段中都会显示：

2022-11-12 09:53:08.349877+0100 Vocab-learner[2394:64531] [plugin] AddInstanceForFactory: No factory registered for id <CFUUID 0x600000354580> F8BB1C28-BAE8-11D6-9C31-00039315CD46
2022-11-12 09:53:19.528945+0100 Vocab-learner[2394:64592] [catalog] Unable to list voice folder
2022-11-12 09:53:19.539617+0100 Vocab-learner[2394:64592] [catalog] Unable to list voice folder
2022-11-12 09:53:19.543384+0100 Vocab-learner[2394:64592] [catalog] Unable to list voice folder
2022-11-12 09:53:19.551385+0100 Vocab-learner[2394:64592] [catalog] Unable to list voice folder
2022-11-12 09:53:19.566548+0100 Vocab-learner[2394:64916] [AXTTSCommon] File file:///System/Library/PrivateFrameworks/TextToSpeechMauiSupport.framework/Resources/TTSResources/en-US/Samantha/Contents/user_rules.txt contained data that was not null terminated
2022-11-12 09:53:19.573183+0100 Vocab-learner[2394:64916] [AXTTSCommon] File file:///tmp/com.apple.mobileassetd/AssetsV2/com_apple_MobileAsset_Trial_Siri_SiriTextToSpeech/purpose_auto/253115073e2b38c109deaac3e52d26ad44a84148.asset/AssetData/vocalizer-user-dict.dat contained data that was not null terminated

这意味着什么？我需要做什么？

我改变了语言，但它也不起作用。

信用至@节奏拳手 https://stackoverflow.com/users/22147/rhythmic-fistman的评论，正确地识别了问题！

The AVSpeechSynthesizer超出了范围，因为当readOut函数退出，因此在 TTS 播放之前它被释放。解决方案是保留对AVSpeechSynthesizer在你看来的成员变量中，并转换readOut进入你认为的方法：

struct VocabDetailView: View {
    let synth = AVSpeechSynthesizer()
    
    private func readOut(text: String) {
        let utterance = AVSpeechUtterance(string: text)
        utterance.voice = AVSpeechSynthesisVoice(language: "en-US")

        synth.speak(utterance)
    }

    var body: some View {
        HStack{
            Button("Play") {
                readOut(text: "test")
            }
        }
    }
}

注意：OP 中包含的日志行仍会打印出来，但是是错误的并且不会影响 TTS。