iOS - 如何在 AVPlayer 中实现 seektotime(从 URL 播放歌曲)？

Question

我想在 AVPlayer 中实现 Scrubber (UISlider)。我试过但没有完全成功(有时 slider 显示不正确的值或有时进度条)。任何建议都会很棒。

-(void)playButtonClicked
{

    // checks internet connnection : working or not

    if([InternetUtility testInternetConnection])

    {

        if (audioButton.selected)
        {
            audioButton.selected = NO;
            printf("\n\ndo audioButton.selected = NO; \n\n");

        }

        else
        {
            printf("\n\ndo audioButton.selected = YES; \n\n");
            audioButton.selected = YES;
        }

        if (!isAlredayPlaying) {
        printf("\n\nStarted song from 0\n");
        isAlredayPlaying=YES;




        NSURL *url = [NSURL URLWithString:AUDIO_FILE_URL];


        playerItem = [AVPlayerItem playerItemWithURL:url];



        player = [AVPlayer playerWithPlayerItem:playerItem];
        player.volume=5.0;
        [self.audioSliderBar setMinimumValue:0.0];
        nsTimer=[NSTimer scheduledTimerWithTimeInterval:1.0/60.0 target:self selector:@selector(updateTime:) userInfo:nil repeats:YES];
        [player play];


    }

    else
    {
        if (isCurrentlyPlaying)

        {
            [nsTimer invalidate];
            isCurrentlyPlaying=NO;
            [player pause];


        }
        else
        {
            nsTimer=[NSTimer scheduledTimerWithTimeInterval:1.0/60.0 target:self selector:@selector(updateTime:) userInfo:nil repeats:YES];
            isCurrentlyPlaying=YES;
            [player play];

        }

     }
}      // internet connection check funtion, ended


    else {
        [ViewUtilities showAlert:INTERNET_CONNETION_TITLE :INTERNET_CONNECTION_MESSAGE];

    }
}

    - (void)updateTime:(NSTimer *)timer {


    currentTime = CMTimeGetSeconds(playerItem.currentTime);

    duration = CMTimeGetSeconds(playerItem.duration);


    if (currentTime==duration) {
        [self itemDidFinishPlaying];

    }

    [ self.audioSliderBar setValue:(currentTime/duration)];

    float minutes = floor(currentTime/60);
    seconds =currentTime - (minutes * 60);

    float duration_minutes = floor(duration/60);
    duration_seconds =
    duration - (duration_minutes * 60);



    NSString *timeInfoString = [[NSString alloc]
                                initWithFormat:@"%0.0f:%0.0f",
                                minutes, seconds ];//],
    //duration_minutes, duration_seconds];

    if  (!(player.currentItem && player.rate != 0 )&& isCurrentlyPlaying)
    {
        if (audioPlayerWillStop) {

            isAlredayPlaying=NO;
            [nsTimer invalidate];

        }

        else {

            [player play];
            printf("\n\n\n Force to play song...");

        }


    }
    self.audioCurrentTimeLabel.text = timeInfoString;

}

- (IBAction)audioPlayerValueChanged:(UISlider *)aSlider {

 CMTime newSeekTime = CMTimeMakeWithSeconds(aSlider.value*seconds,1) ;
[player seekToTime:newSeekTime];

//此代码无法完全正常工作( slider 值不断上升)请帮忙

}

Answer 1

您可以使用我实现的方法。此代码运行良好。

        #define NSEC_PER_SEC 1000000000ull
        -(void)funSeekPlayer
        {
               CMTime playerDuration = [self playerItemDuration];
               if (CMTIME_IS_INVALID(playerDuration)) {
                 return;
               }

               float minValue = [aSlider minimumValue];
               float maxValue = [aSlider maximumValue];
               float value = [aSlider value];

               double time = duration * (value - minValue) / (maxValue - minValue);

               [player seekToTime:CMTimeMakeWithSeconds(CMTimeMakeWithSeconds(time, NSEC_PER_SEC), NSEC_PER_SEC) completionHandler:^(BOOL finished) {
                   dispatch_async(dispatch_get_main_queue(), ^{
                    // Do Your next task
                   });
               }];

         }

         - (CMTime)playerItemDuration
         {
            AVPlayerItem *playerItem = [player currentItem];
            if (playerItem.status == AVPlayerItemStatusReadyToPlay)
            {
                return([playerItem duration]);
            }

            return(kCMTimeInvalid);
         }