Question

您好，我有一个功能，当您单击导航中的链接时，正文的内容会切换，我将其与 this 问题中的一个小脚本相结合，效果很好。唯一的问题是，如果您单击链接而不滚动，则除非您滚动至少 1 像素，否则图像不会显示。所以我想知道是否有解决方案。 JSFiddle。

附带问题：是否可以等到页面完全向上滚动时才显示内容？

脚本：

$(window).on("load",function() {
  function fade(pageLoad) {
    var windowTop=$(window).scrollTop(), windowBottom=windowTop+$(window).innerHeight();
    var min=0, max=1, threshold=0.01;
    
    $(".fade").each(function() {
      /* Check the location of each desired element */
      var objectHeight=$(this).outerHeight(), objectTop=$(this).offset().top, objectBottom=$(this).offset().top+objectHeight;
      
      /* Fade element in/out based on its visible percentage */
      if (objectTop < windowTop) {
        if (objectBottom > windowTop) {$(this).fadeTo(0,min+((max-min)*((objectBottom-windowTop)/objectHeight)));}
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}
      } else if (objectBottom > windowBottom) {
        if (objectTop < windowBottom) {$(this).fadeTo(0,min+((max-min)*((windowBottom-objectTop)/objectHeight)));}
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}
      } else if ($(this).css("opacity")<=max-threshold || pageLoad) {$(this).fadeTo(0,max);}
    });
  } fade(true); //fade elements on page-load
  $(window).scroll(function(){fade(false);}); //fade elements on scroll
});

Answer 1

您可以通过在 fade 之外使用 load event listener 方法来实现它，这将使其在任何地方都可用。然后通过点击 nav buttons 调用它。

见下面的js：

$(window).on("load",function() {
 this.fade(true); //fade elements on page-load
  $(window).scroll(function(){this.fade(false);}); //fade elements on scroll
});

//Take below fade method outside of the load event listener.

  function fade(pageLoad) {
    var windowTop=$(window).scrollTop(), windowBottom=windowTop+$(window).innerHeight();
    var min=0, max=1, threshold=0.01;
    
    $(".fade").each(function() {
      /* Check the location of each desired element */
      var objectHeight=$(this).outerHeight(), objectTop=$(this).offset().top, objectBottom=$(this).offset().top+objectHeight;
      
      /* Fade element in/out based on its visible percentage */
      if (objectTop < windowTop) {
        if (objectBottom > windowTop) {$(this).fadeTo(0,min+((max-min)*((objectBottom-windowTop)/objectHeight)));}
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}
      } else if (objectBottom > windowBottom) {
        if (objectTop < windowBottom) {$(this).fadeTo(0,min+((max-min)*((windowBottom-objectTop)/objectHeight)));}
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}
      } else if ($(this).css("opacity")<=max-threshold || pageLoad) {$(this).fadeTo(0,max);}
      
    });
  }

    
// change activenav class, show the clicked element only and hide the others https://codepen.io/MohdHussein/pen/MWKEvdp


// grab all the buttons
let Buttons = document.querySelectorAll(".selectSection button");

// loop through the buttons using for..of 
for (let button of Buttons) {
  // listen for a click event 
  button.addEventListener('click', (e) => {
    // et = event target
    const et = e.target;
    // slect activenav class
    const activenav = document.querySelector(".activenav");
    // check for the button that has activenav class and remove it
    if (activenav) {
      activenav.classList.remove("activenav");
    }
    // add activenav class to the clicked element 
    et.classList.add("activenav");

    // select all classes with the name content
    let allContent = document.querySelectorAll('.contentsec');

    // loop through all content classes
    for (let contentsec of allContent) {
      // display the content if the class has the same data-attribute as the button 
      if (contentsec.getAttribute('data-number') === button.getAttribute('data-number')) {
        contentsec.style.display = "block";
      }
      // if it's not equal then hide it.
      else {
        contentsec.style.display = "none";
      }
    }
    this.fade(true); //Call fade method on click 
  });
}

您可以对其进行测试here。

单击导航链接时更新功能

1 个答案: