如何在这些元素上添加过渡到 hide() 和 show() 的效果？答案

【问题标题】：How do I add transition to the effect of hide() and show() on these elements?如何在这些元素上添加过渡到 hide() 和 show() 的效果？
【发布时间】：2016-01-30 10:20:02
【问题描述】：

在下面的 SSCCE 中，如何使用 show() 为 .items 的外观设置动画，并使用 hide() 为它们的消失设置动画，使其看起来像 item5、item6、item7、@ 987654329@已飞入视口？

也就是说，我想要的是当.next-arrow被点击时，例如第一次，隐藏item1，item2，item3，item4，并显示@ 987654335@、item6、item7、item8，是“过渡”的——就像新页面流入视口in this website.

我该怎么做？

$(document).ready(function() {
  //alert('ready');//check

  var numberOfItems = $('.item').length;
  //alert('numberOfItems => ' + numberOfItems);//check

  displayNextArrowOnCondition();
  displayPreviousArrowOnCondition();



  /**
   *
   **/
  $('a.next-arrow').click(function(event) {
    event.preventDefault();

    var currentFirstItem = getCurrentFirstItem(); // Difference between var and no var SO: If you're in the global scope then there's no difference. If you're in a function then var will create a local variable, "no var" will look up the scope chain until it finds the variable or hits the global scope (at which point it will create it):

    $('div.item' + currentFirstItem).hide(); //We don't need to have the condition of checking this element's existence because the next-arrow whose handler this method is, appears only if the numberOfItems is greater than the id of the item with the greatest id among the elements currently visible on the screen.
    if (('div.item' + (currentFirstItem + 1)).length) { //SO: How can I check the existence of an element in jQuery?? In JavaScript, everything is truthy or falsy and for numbers, 0 means false, everything else true. So you could write: "if ($(selector).length)" - and you don't need that > 0 part.
      $('div.item' + (currentFirstItem + 1)).hide();
    }
    if (('div.item' + (currentFirstItem + 2)).length) {
      $('div.item' + (currentFirstItem + 2)).hide();
    }
    if (('div.item' + (currentFirstItem + 3)).length) {
      $('div.item' + (currentFirstItem + 3)).hide();
    }

    hidePreviousArrow();
    hideNextArrow();

    displayPreviousArrowOnCondition();
    displayNextArrowOnCondition();
  });


  /**
   *
   **/
  $('a.previous-arrow').click(function(event) {
    event.preventDefault();

    var currentFirstItem = getCurrentFirstItem();

    $('div.item' + (currentFirstItem - 1)).show();

    if (('div.item' + (currentFirstItem - 2)).length) {
      $('div.item' + (currentFirstItem - 2)).show();
    }
    if (('div.item' + (currentFirstItem - 3)).length) {
      $('div.item' + (currentFirstItem - 3)).show();
    }
    if (('div.item' + (currentFirstItem - 4)).length) {
      $('div.item' + (currentFirstItem - 4)).show();
    }

    hidePreviousArrow();
    hideNextArrow();

    displayPreviousArrowOnCondition();
    displayNextArrowOnCondition();
  });



  /**
   * DISPLAY NEXT ARROW WHEN
   * 1. NUMBER OF ITEMS IS GREATER THAN THE id OF THE LAST ITEM DISPLAYED IN THE CURRENT VIEWPORT
   **/
  function displayNextArrowOnCondition() {
    //alert('displayNextArrowOnCondition called');//check
    //Iterate through items in OPPOSTIE order, and when found the first one which is not hidden by hide() or display:none, assign it to currentLastItem (because this is the first item in the viewport), and break out from the loop.
    var currentLastItem = getCurrentLastItem();
    //alert('currentLastItem -> ' + currentLastItem);//check
    if (currentLastItem < numberOfItems) {
      $('a.next-arrow').css('display', 'block');
      $('.wrapper').mouseover(function() {
        //$('a.next-arrow').css('visibility', 'visible');
      });
      $('.wrapper').mouseleave(function() {
        //$('a.next-arrow').css('visibility', 'hidden');
      });
    }
  }


  /**
   * DISPLAY PREVIOUS ARROW WHEN
   * 1. THE id OF THE FIRST DISPLAYED ITEM IS GREATER THAN 4
   **/
  function displayPreviousArrowOnCondition() {
    //Iterate through items in order, and when found the first one which is not hidden by hide() or display:none, assign it to currentFirstItem (because this is the first item in the viewport), and break out from the loop.
    var currentFirstItem = getCurrentFirstItem();
    if (currentFirstItem > 4) {
      $('a.previous-arrow').css('display', 'block');
      $('.wrapper').mouseover(function() {
        $('a.previous-arrow').css('visibility', 'visible');
      });
      $('.wrapper').mouseleave(function() {
        $('a.previous-arrow').css('visibility', 'hidden');
      });
    }
  }


  /**
   * DISPLAY:NONE NEXT ARROW IF IT IS VISIBLE
   **/
  function hideNextArrow() {
    //alert('hideNextArrow called');//check
    if ($('a.next-arrow').css('display').toLowerCase() == 'block') { //The == operator will compare for equality after doing any necessary type conversions. The === operator will not do the conversion, so if two values are not the same type === will simply return false.| Just in case anyone was wondering in 2012: === is way faster than ==. jsperf.com/comparison-of-comparisons.
      //alert('YES if ($(\'a.next-arrow\').attr(\'display\').toLowerCase() == \'block\'). SO I AM CHANGING IT TO none.');//check
      $('a.next-arrow').css('display', 'none');
    } //else { alert('NO  if ($(\'a.next-arrow\').attr(\'display\').toLowerCase() == \'block\').'); } //check
  }


  /**
   * DISPLAY:NONE PREVIOUS ARROW IF IT IS VISIBLE
   **/
  function hidePreviousArrow() {
    //alert('hidePreviousArrow called');//check
    //alert($('a.previous-arrow').css('display'));//check
    if ($('a.previous-arrow').css('display') == 'block') {
      //alert('YES if ($(\'a.previous-arrow\').attr(\'display\').toLowerCase() == \'block\'). SO I AM CHANGING IT TO none.');//check
      $('a.previous-arrow').css('display', 'none');
    } //else { alert('NO  if ($(\'a.previous-arrow\').attr(\'display\').toLowerCase() == \'block\').'); } //check
  }


  /**
   *
   **/
  function getCurrentFirstItem() {
    for (i = 1; i <= numberOfItems; i++) {
      if ($("#" + i).visible(true, true)) {
        //alert('YES if (  $("#"+i).visible(true, true)  )');//check
        currentFirstItem = i;
        break;
      } //else { //alert('NO if (  $("#"+i).visible(true, true)  )'); }//check 
    }
    //alert('currentFirstItem -> ' + currentFirstItem);//check
    return currentFirstItem;
  }


  /**
   *
   **/
  function getCurrentLastItem() {
    for (j = numberOfItems; j >= 1; j--) {
      if ($("#" + j).visible(true, true)) {
        //alert("YES if (  $(\"#\"+j).visible(true, true) ) ");//check
        currentLastItem = j;
        break;
      } //else { //alert('NO if (  $("#"+j).visible(true, true) )'); } //check
    }
    //alert('currentLastItem -> ' + currentLastItem);//check
    return currentLastItem;
  }

});

html,
body,
body div,
span,
object,
iframe,
h1,
h2,
h3,
h4,
h5,
h6,
p,
blockquote,
pre,
abbr,
address,
cite,
code,
del,
dfn,
em,
img,
ins,
kbd,
q,
samp,
small,
strong,
sub,
sup,
var,
b,
i,
dl,
dt,
dd,
ol,
ul,
li,
fieldset,
form,
label,
legend,
table,
caption,
tbody,
tfoot,
thead,
tr,
th,
td,
article,
aside,
figure,
footer,
header,
hgroup,
menu,
nav,
section,
time,
mark,
audio,
video,
details,
summary {
  margin: 0px;
  padding: 0px;
  border: 0px none;
  background: transparent none repeat scroll 0% 0%;
  font-size: 100%;
  vertical-align: baseline;
}
.wrapper {
  position: relative;
  white-space: nowrap;
  overflow: hidden;
}
div.item {
  /*position:absolute;*/
  display: inline-block;
  width: 25%;
  height: 25vw;
}
.item1 {
  left: 0%;
  background-color: wheat;
}
.item2 {
  left: 25%;
  background-color: pink;
}
.item3 {
  left: 50%;
  background-color: beige;
}
.item4 {
  left: 75%;
  background-color: gainsboro;
}
.item5 {
  left: 100%;
  background-color: coral;
}
.item6 {
  left: 125%;
  background-color: crimson;
}
.item7 {
  left: 150%;
  background-color: aquamarine;
}
.item8 {
  left: 175%;
  background-color: darkgoldenrod;
}
.item9 {
  left: 200%;
  background-color: khaki;
}
.item10 {
  left: 225%;
  background-color: indianred;
}
.item11 {
  left: 250%;
  background-color: mediumspringgreen;
}
.previous-arrow,
.next-arrow {
  width: 30px;
  height: 50%;
  top: 50%;
  position: absolute;
  opacity: 0.7;
  color: white;
  background-repeat: no-repeat;
  margin-top: -30px;
  display: none;
}
.previous-arrow {
  background-image: url(a2.png);
  left: 0px;
}
.next-arrow {
  background-image: url(b2.png);
  right: 0px;
}
.previous-arrow,
.next-arrow {
  opacity: 1;
}
body {
  background-color: black;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://cdn.jsdelivr.net/jquery.visible/1.1.0/jquery.visible.min.js"></script>

<div class="wrapper">
  <a class="previous-arrow" href="">&gt;</a>-->
  <!--
		-->
  <div id="1" class="item item1 wheat">a.</div>
  <!--
		-->
  <div id="2" class="item item2 pink">a.</div>
  <!--
		-->
  <div id="3" class="item item3 beige">a.</div>
  <!--
		-->
  <div id="4" class="item item4 gainsboro">a.</div>
  <!--
		-->
  <div id="5" class="item item5 coral">a.</div>
  <!--
		-->
  <div id="6" class="item item6 crimson">a.</div>
  <!--
		-->
  <div id="7" class="item item7 darkgoldenrod">a.</div>
  <!--
		-->
  <div id="8" class="item item8 aquamarine">a.</div>
  <!--
		-->
  <div id="9" class="item item9 aquamarine">a.</div>
  <!--
		-->
  <div id="10" class="item item10 aquamarine">a.</div>
  <!--
		-->
  <div id="11" class="item item11 aquamarine">a.</div>
  <!--
		--><a class="next-arrow" href="">&lt;</a>	
</div>

【问题讨论】：

尝试使用淡入淡出和淡入淡出并添加持续时间，我不知道您是否可以为其添加方向。
您还可以充分利用.animate()，它可以让您为更多的css属性设置动画，而不是像.hide()、.show()等速记函数api.jquery.com/animate

标签： javascript jquery css css-transitions transition

【解决方案1】：

您可以使用.hide()、fadeOut()、show()、fadeIn()

示例代码

您可以使用.show() 来显示匹配的元素。

当用户在输入文本上键入内容时显示列表的示例代码。

    $("#search-guide").focusin(function () {
      $("#list-user-guides").show();
    });

您可以使用.hide() 来隐藏匹配的元素。

当用户单击屏幕上的其他位置时的示例代码隐藏列表。

    $("#search-guide").focusin(function () {
      $("#list-user-guides").hide();
    });

但我个人使用.fadeIn() 和fadeOut()，因为这两种方法具有流畅的动画效果。

您可以按照上述答案查看官方文档。

【讨论】：

【解决方案2】：

您可以为show() 函数传递一个参数，例如.show('slow')，它会像fadeIn() 函数一样执行动画。

用例子检查documentation

【讨论】：

【解决方案3】：

如果你只想使用show()和hide()，你可以使用show('slow')和hide('slow')等。除此之外还有很多方法和效果可以使用。

请点击此链接了解有多少种方法可以做到这一点。

jQuery Effects

【讨论】：

【解决方案4】：

您可以使用 css 过渡或 css 动画。像这样的动画：

定义 css 类规则并将类名称分配给您想要动画的元素

.doFadeIn {
    -webkit-animation:fadeInSlide forwards ease-in 150ms;
    animation:fadeInSlide forwards ease-in 150ms;
}
.doFadeOut {
    -webkit-animation:fadeOutSlideDown forwards ease-out 150ms;
    animation:fadeOutSlideDown forwards ease-out 150ms;
}

为动画定义关键帧

    @keyframes fadeInSlide
    {
         0% { opactity:0; transform: translateX(-100px); }
         100% { opactity:1; transform: translateX(0); }
    }

将 doFadeIn 分配给元素的类名时，它们将：淡入 - 不透明度：0 到 1（0% 可见到 100% 可见）沿水平轴 (X) 向元素原始位置左侧 100px 移动到其原始位置。

它将在 150 毫秒的持续时间内执行此操作

<div id="my-widget1" class="my-widget"><div>
  
<div id="my-widget1" class="my-widget doFadeIn"><div>

【讨论】：