ios - AVSpeechSynthesizer - 使用 AVSpeechBoundaryImmediate 时不会停止

Question

我有两个视图控制器。一和二。

1. 在 oneViewController 上，有一个使用 Storyboard 调用 TwoViewController 的按钮 - 工作正常
2. 在 TwoViewController 上有一个按钮，可以使用按钮（Listen Button）读取一些文本 - 工作正常
3. TwoViewController 上有返回按钮，可将您带回 oneViewController。

问题：

如果两次单击“听”按钮并按下“返回”按钮，则视图控制器会从“二”变为“一”，但语音仍在后台进行。有人可以帮忙阻止演讲吗？

TwoViewController 上的代码：

AVSpeechSynthesizer *synth;

-(IBAction) Back:(id)sender
{
    [_synth stopSpeakingAtBoundary: AVSpeechBoundaryImmediate]; --not working
    [self dismissViewControllerAnimated:YES completion:nil]; - working fine.
}

-(void) viewDidDisappear:(BOOL)animated
{
    [_synth stopSpeakingAtBoundary:AVSpeechBoundaryImmediate]; --not working
    [self dismissViewControllerAnimated:YES completion:nil];
}

-(IBAction)listenButton:(id)sender
{
    AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@"I am running a test."];
    [utterance setRate:0.18f];
    _synth=[[AVSpeechSynthesizer alloc] init];
    [_synth speakUtterance:utterance];

}

注意：如果单击“收听”按钮一次，然后单击“返回”按钮，则不会发生此问题。仅当多次单击“收听”按钮然后单击“返回”按钮时才会出现问题。

Answer 1

试试这个暂停，恢复和停止选项

-(void)stopSpeechReading
{
    if([synthesize isSpeaking]) {
        NSLog(@"Reading has been stopped");
        [synthesize stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@""];
        [synthesize speakUtterance:utterance];
        [synthesize stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
    }
}

-(void)pauseSpeechReading
{
    if([synthesize isSpeaking]) {
        NSLog(@"Reading paused");
        [synthesize pauseSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@""];
        [synthesize speakUtterance:utterance];
        [synthesize pauseSpeakingAtBoundary:AVSpeechBoundaryImmediate];
    }
}

-(void)resumeSpeechReading
{
     NSLog(@"Reading resumed");
    [synthesize continueSpeaking];
}