mousewheel和if语句jquery(mousewheel and if statements jquery)

 我想要做的就是当你尝试向上或向下滚动它时调用一个改变页面的功能。 我的身体overflow:hidden 。 
 
 我正在使用名为https://github.com/jquery/jquery-mousewheel'>mousewheel的jquery插件 
 
 这是我的代码： 
 
$('#body').on('mousewheel', function(event) {

  if( event.originalEvent.detail > 0 || event.originalEvent.wheelDelta < 0 ) {
    //scroll down
    if(document.getElementById('pgcount').innerHTML == 'Page 1') scrollDown(2);
    if(document.getElementById('pgcount').innerHTML == 'Page 2') scrollDown(3);
    if(document.getElementById('pgcount').innerHTML == 'Page 3') scrollDown(4);
    if(document.getElementById('pgcount').innerHTML == 'Page 4') scrollDown(5);
  } else {
    //scroll up
    if(document.getElementById('pgcount').innerHTML == 'Page 2') scrollUp(1);
    if(document.getElementById('pgcount').innerHTML == 'Page 3') scrollUp(2);
    if(document.getElementById('pgcount').innerHTML == 'Page 4') scrollUp(3);
    if(document.getElementById('pgcount').innerHTML == 'Page 5') scrollUp(4);
  }
  //prevent page fom scrolling
  return false;

});
 
 出于某种原因，它在向上滚动时有效，但当您向下滚动时，它会直接进入第5页（最后一个）。 当我将console.log(document.getElementById('pgcount').innerHTML)到每个用于向下滚动的if语句时，记录了这个： 
 
Page 1
Page 2
Page 3
Page 4
 
 我不明白为什么它会向上滚动而不是向下滚动。 我知道被调用的函数（scrollDown）不是问题，因为它从控制台调用时可以正常工作。 
 
 提前致谢 

What I'm trying to do is make it so when you try to scroll up or down it calls a function that changes the page. My body has overflow:hidden.
 
I'm using the jquery plugin called https://github.com/jquery/jquery-mousewheel'>mousewheel
 
This is my code:
 
$('#body').on('mousewheel', function(event) {

  if( event.originalEvent.detail > 0 || event.originalEvent.wheelDelta < 0 ) {
    //scroll down
    if(document.getElementById('pgcount').innerHTML == 'Page 1') scrollDown(2);
    if(document.getElementById('pgcount').innerHTML == 'Page 2') scrollDown(3);
    if(document.getElementById('pgcount').innerHTML == 'Page 3') scrollDown(4);
    if(document.getElementById('pgcount').innerHTML == 'Page 4') scrollDown(5);
  } else {
    //scroll up
    if(document.getElementById('pgcount').innerHTML == 'Page 2') scrollUp(1);
    if(document.getElementById('pgcount').innerHTML == 'Page 3') scrollUp(2);
    if(document.getElementById('pgcount').innerHTML == 'Page 4') scrollUp(3);
    if(document.getElementById('pgcount').innerHTML == 'Page 5') scrollUp(4);
  }
  //prevent page fom scrolling
  return false;

});
 
For some reason it works when scrolling up but when you scroll down it goes straight to page 5 (the last one). When i added console.log(document.getElementById('pgcount').innerHTML) to each if statement for scrolling down it logged this:
 
Page 1
Page 2
Page 3
Page 4
 
I don't understand why it would work scrolling up but not down. I know that the function being called (scrollDown) isn't the problem as it works when called from the console.
 
Thanks in advance

原文：https://stackoverflow.com/questions/39318681