为什么这个 Jquery 动画的回调函数会在动画执行之前执行？

Question

我有这个javascript：

        $('.carouselItem.' + currentCarouselItem).animate({left: '975px'}, 'slow', function(){
            $(this).removeClass('active');
            $(this).attr('style','');
            var nextItem = currentCarouselItem + 1;
            if (nextItem == 7) {
                nextItem = 1;
            }
            $('.carouselItem.' + nextItem).animate({left: '110px'}, 'slow', function(){
                $(this).addClass('active');
            });
            }
        })

第一个动画的回调在第一个动画完成之前执行。知道为什么吗？

如果对您有帮助的话，这里是完整的代码：

var currentCarouselItem = 1; //set carousel to first slide
    var runCarousel = 1;
    var carouselInterupt = 0;


function autoScroll(){

        if (runCarousel == 1) {
            if (carouselInterupt == 0){

            $('.carouselItem.' + currentCarouselItem).animate({left: '975px'}, 'slow', function(){
                $(this).removeClass('active');
                $(this).attr('style','');
                var nextItem = currentCarouselItem + 1;
                if (nextItem == 7) {
                    nextItem = 1;
                }
                $('.carouselItem.' + nextItem).animate({left: '110px'}, 'slow', function(){
                    $(this).addClass('active');
                });
                }
            })

            if (currentCarouselItem == 6) {
                currentCarouselItem = 1;
            } else {
                currentCarouselItem++;
            }

        }
    }

    setTimeout(autoScroll, 3000);

}

$(function(){

$(window).load(function(){

    autoScroll();

});

});

这里是受影响的 html（很多 lorem ipsum :)）：

    <div id= "wrapper">
    <div id= "teasertext" class="active carouselItem 1">


        <div class= "title"> <h1> Growing Your Business Online</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "viewservices" class="teaserBttn"><a href="#" rel="#">View Services</a></div>


    </div>



    <div id= "about-teasertext" class="carouselItem 2">


        <div class= "about-title"> <h1> About</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "view-about" class="teaserBttn"><a href="#" rel="#">View About</a></div>


    </div>



    <div id= "portfolio-teasertext" class="carouselItem 3">


        <div class= "portfolio-title"> <h1> Portfolio</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "view-portfolio" class="teaserBttn"><a href="#" rel="#">View Portfolio</a></div>


    </div>



    <div id= "team-teasertext" class="carouselItem 4">

    <div class= "team-title"> <h1> Team</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "view-teams" class="teaserBttn"><a href="#" rel="#">View Team</a></div>


    </div>



    <div id= "process-teasertext" class="carouselItem 5">
    <div class= "process-title"> <h1> Process</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "view-process" class="teaserBttn"><a href="#" rel="#">View Process</a></div>


    </div>


    <div id= "packages-teasertext" class="carouselItem 6">
    <div class= "packages-title"> <h1> Packages</h1> </div>

        <p>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        </p>
    <div id= "view-packages" class="teaserBttn"><a href="#" rel="#">View Packages</a></div>


    </div>


</div>

Answer 1

你好像多了一个大括号}：

 $('.carouselItem.' + currentCarouselItem).animate({left: '975px'}, 'slow', function(){
    $(this).removeClass('active');
    $(this).attr('style','');
    var nextItem = currentCarouselItem + 1;
    if (nextItem == 7) {
      nextItem = 1;
    }
    $('.carouselItem.' + nextItem).animate({left: '110px'}, 'slow', function(){
       $(this).addClass('active');
     });
  }   //<----- HERE
  })