AVSpeechSynthesizer 没有停止

Question

我在我的 iOS 应用程序中使用 AVSpeechSynthesizer 进行 TTS。但是没有调用 didFinishSpeechUtterance 方法。

这是我在 .h 中的代码：

#import <AVFoundation/AVFoundation.h>

@interface EmailViewController : UIViewController <UITextFieldDelegate, AVSpeechSynthesizerDelegate>

@property (nonatomic, strong) AVSpeechSynthesizer* talker;

这是在.m中

- (void) startTalking {
    NSString *hi = [NSString stringWithFormat:@"%@", humanLanguageArray[speaknumber]];
    AVSpeechUtterance* utter = [[AVSpeechUtterance alloc] initWithString:hi];
    utter.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"en-US"];
    [utter setRate:0.2f];
    if (!self.talker) {
        self.talker = [AVSpeechSynthesizer new];
    }
    self.talker.delegate = self;
    [self.talker speakUtterance:utter];
}
- (void)stopSpeech
{
    AVSpeechSynthesizer *talked = [[AVSpeechSynthesizer alloc] init];
    if([talked isSpeaking]) {
        [talked stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@""];
        [talked speakUtterance:utterance];
        [talked stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
    }
}
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utteranc
{
    if (speaknumber < (length-1)) {
        speaknumber += 1;
        self.talker.delegate = self;
        NSString *hi = [NSString stringWithFormat:@"%@", humanLanguageArray[speaknumber]];
        AVSpeechUtterance *utter = [[AVSpeechUtterance alloc] initWithString:hi];
        utter.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"en-US"];
        [utter setRate:0.2f];
        if (!self.talker) {
            self.talker = [AVSpeechSynthesizer new];
        }
        [self.talker speakUtterance:utter];
    } else if (speaknumber >= length) {
    }
}

如果我调用 stopSpeech，它不会停止说话，它会一直说话直到speaknumber >= length。有谁知道如何解决这个问题？

Answer 1

为什么还要在 stopSpeech 中实例化 AVSpeechSynthesizer？

- (void)stopSpeech
{
    AVSpeechSynthesizer *talked = self.talker;
    if([talked isSpeaking]) {
        [talked stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@""];
        [talked speakUtterance:utterance];
        [talked stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
    }
}

说话的实例是 self.talker，不是吗？