Question

我正在使用AVSpeechSynthesizer播放文字。我有一系列的话语可以玩。

    NSMutableArray *utterances = [[NSMutableArray alloc] init];
    for (NSString *text in textArray) {
        AVSpeechUtterance *welcome = [[AVSpeechUtterance alloc] initWithString:text];
        welcome.rate = 0.25;
        welcome.voice = voice;
        welcome.pitchMultiplier = 1.2;
        welcome.postUtteranceDelay = 0.25;
        [utterances addObject:welcome];
    }
    lastUtterance = [utterances lastObject];
    for (AVSpeechUtterance *utterance in utterances) {
        [speech speakUtterance:utterance];
    }

我有一个取消按钮停止说话。当我说出第一个话语时单击取消按钮时，语音停止并清除队列中的所有话语。如果在说出第一个话语（即第二个话语）之后按下取消按钮，则停止讲话不会刷新话语队列。我正在使用的代码是：

  [speech stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];

有人可以确认这是API中的错误还是我错误地使用了API？如果是错误，是否有解决此问题的解决方法？

Answer 1

我找到了解决方法：

- (void)stopSpeech
{
    if([_speechSynthesizer isSpeaking]) {
        [_speechSynthesizer stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:@""];
        [_speechSynthesizer speakUtterance:utterance];
        [_speechSynthesizer stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];    
    }
}

调用stopSpeakingAtBoundary:，将空话发入队列并再次致电stopSpeakingAtBoundary:以停止并清理队列。

Answer 2

很可能是一个错误，因为在第一个话语之后没有调用委托方法合成器didCancelSpeechUtterance ;

解决方法是链接话语而不是将它们放在数组中并立即排队。

使用委托方法 synthesizer didFinishSpeechUtterance 递增数组指针并说出该数组中的下一个文本。然后，在尝试停止语音时，在尝试说出下一个文本之前设置在此委托方法中检查的BOOL。

例如：

1）在正在进行语音合成的视图控制器中实现协议

#import <UIKit/UIKit.h>
@import AVFoundation;
@interface ViewController : UIViewController <AVSpeechSynthesizerDelegate>

@end

2）实例化AVSpeechSynthesizer并将其委托设置为self

speechSynthesizer   = [AVSpeechSynthesizer new];
speechSynthesizer.delegate = self;

3）使用话语计数器，在开始讲话时设置为零

4）使用一系列文字说话

textArray           = @[@"Mary had a little lamb, its fleece",
                        @"was white as snow",
                        @"and everywhere that Mary went",
                        @"that sheep was sure to go"];

5）添加委托方法didFinishSpeechUtterance来说出数组中的下一个话语文本和增加话语计数器

- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utterance{
    if(utteranceCounter < utterances.count){
        AVSpeechUtterance *utterance = utterances[utteranceCounter];
        [synthesizer speakUtterance:utterance];
        utteranceCounter++;
    }
}

5）停止说话，将话语计数器设置为文本数组的计数，并尝试让合成器停止

utteranceCounter = utterances.count;

BOOL speechStopped =  [speechSynthesizer stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
if(!speechStopped){
    [speechSynthesizer stopSpeakingAtBoundary:AVSpeechBoundaryWord];
}

6）再次发言时，将话语计数器重置为零

Answer 3

这里的所有答案都失败了，我想出的就是停止合成器，然后重新实例化它：

- (void)stopSpeech
{
    if([_speechSynthesizer isSpeaking]) {
        [_speechSynthesizer stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
        _speechSynthesizer = [AVSpeechSynthesizer new];
        _speechSynthesizer.delegate = self;
    }
}

Answer 4

我做了类似SPA提到的事情。从循环中一次说出一个项目。这是想法..

NSMutableArray *arr; //array of NSStrings, declared as property
AVSpeechUtterance *currentUtterence;  //declared as property
AVSpeechSynthesizer *synthesizer; //property

- (void) viewDidLoad:(BOOL)anim
{
    [super viewDidLoad:anim];
    synthesizer = [[AVSpeechSynthesizer alloc]init];

    //EDIT -- Added the line below
    synthesizer.delegate = self;

    arr = [self populateArrayWithString]; //generates strings to speak
}

//assuming one thread will call this
- (void) speakNext
{
   if (arr.count > 0)
   {
        NSString *str = [arr objectAtIndex:0];
        [arr removeObjectAtIndex:0];
        currentUtterence = [[AVSpeechUtterance alloc] initWithString:str];

        //EDIT -- Commentted out the line below
        //currentUtterence.delegate = self;
        [synthesizer speakUtterance:utteranc];
    }
}

- (void)speechSynthesizer:(AVSpeechSynthesizer *)avsSynthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utterance
{
    if ([synthesizer isEqual:avsSynthesizer] && [utterance isEqual:currentUtterence])
        [self speakNext];
}

- (IBOutlet) userTappedCancelledButton:(id)sender
{
    //EDIT <- replaced the object the method gets called on.
    [synthesizer stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
    [arr removeAllObjects];
}

Answer 5

didCancelSpeechUtterance不能使用相同的AVSpeechSynthesizer对象，即使话语是在didFinishSpeechUtterance方法中链接的。

-(void)speakInternal
{
    speech = [[AVSpeechSynthesizer alloc] init];
    speech.delegate = self;
    [speech speakUtterance:[utterances objectAtIndex:position++]];
}

在speakInternal中，我多次创建AVSpeechSynthesizer对象以确保didCancelSpeechUtterance有效。一种解决方法。

AVSpeechSynthesizer的问题，有任何解决方法吗？

5 个答案: