爲什麼這個jquery動畫的回調函數會在動畫執行之前執行？

Question

我有這個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'); 
      }); 
      } 
     }) 

第一動畫中的回調是在執行前的第一個動畫完成。任何想法爲什麼？

以下是完整的代碼，如果這將是更有幫助：

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(); 

}); 

}); 

這裏是受影響的HTML（很多Lorem存有的:)）：

<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

你似乎有一個特大號支架}：

$('.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 
    })