jQuery旋转项目跟踪

Question

我在网上建立了一些不错的旋转轨迹，并且一切正常，但是唯一的问题是如何获取选定的卡数据ID？ 我尝试了很多解决方案，但搜索失败了，因为旋转后我无法定义所选的卡，因为我想搜索数据库并获取该卡的信息。

var $cardList = $('.cardList').first(),
  $cards = $('.card'),
  width = 100,
  randomize = true,
  distance = 20 * width;

for (var i = 0; i < 50; i++) {
  $cards.clone().appendTo($cardList);
}

function spin() {

  var newMargin = 0,
    newDistance = distance,
    speed = 5000;
  if (randomize) {
    newDistance = Math.floor(Math.random() * $cards.length * 5);
    newDistance += $cards.length * 5;
    newDistance *= width;
  }
  newMargin = -(newDistance);
  $cards.first().animate({
    marginLeft: newMargin
  }, speed);

}

$('#spin').click(function() {
  $cards.first().css('margin-left', 0);
  spin();
  return false;
});

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

.cardList {
  height: 100px;
  width: 302px;
  position: relative;
  margin: 10px;
  border: 1px solid #33e;
  overflow: hidden;
  white-space: nowrap;
}

.card {
  display: inline-block;
  text-align: center;
  height: 100px;
  width: 100px;
  line-height: 100px;
  background-color: #99e;
  font-family: monospace;
  font-size: 2em;
  color: #444;
  border-left: 1px solid #33e;
  border-right: 1px solid #33e;
}

.cardList::before,
.cardList::after {
  content: '';
  display: block;
  z-index: 100;
  width: 0px;
  height: 0px;
  transform: translateX(-50%);
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
}

.cardList::before {
  position: absolute;
  top: 0px;
  left: 50%;
  border-top: 12px solid #33e;
}

.cardList::after {
  position: absolute;
  bottom: 0px;
  left: 50%;
  border-bottom: 12px solid #33e;
}

div.controls,
button {
  margin: 10px;
  padding: 8px;
  font-family: monospace;
}

div.controls input {
  width: 48px;
  padding: 2px;
  text-align: center;
  font-family: monospace;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="cardList">
  <div class="card" data-id="1">1</div>
  <div class="card" data-id="2">2</div>
  <div class="card" data-id="3">3</div>
  <div class="card" data-id="4">4</div>
  <div class="card" data-id="5">5</div>
  <div class="card" data-id="6">6</div>
  <div class="card" data-id="7">7</div>
  <div class="card" data-id="8">8</div>

</div>
<button id="spin">Spin</button>

Answer 1

您甚至可以在微调器启动之前就知道答案。到目前为止，似乎没有任何失败的猜测。

var numCardsPassed = newDistance / 100; 在这里，我将生成的距离除以一张纸牌的宽度，得出多少张纸牌将被随机播放。

var answer = Math.floor(STARTING_INDEX + (numCardsPassed % $cards.length)); 在这里，我计算了经过八次卡旋转numCardsPassed（从索引/卡2开始）后，它将落在哪张卡上。

这种方法的妙处在于，您可以在卡片改组时从数据库中获取数据，这意味着您可以在动画完成后立即显示数据。

// the card the arrows start on, in this case, card 2
const STARTING_INDEX = 2;

var $cardList = $('.cardList').first(),
  $cards = $('.card'),
  width = 100,
  randomize = true,
  distance = 20 * width;

for (var i = 0; i < 50; i++) {
  $cards.clone().appendTo($cardList);
}

function spin() {

  var newMargin = 0,
    newDistance = distance,
    speed = 5000;
  if (randomize) {
    newDistance = Math.floor(Math.random() * $cards.length * 5);
    newDistance += $cards.length * 5;
    newDistance *= width;
  }

  var numCardsPassed = newDistance / 100;
  var answer = Math.floor(STARTING_INDEX + (numCardsPassed % $cards.length));
  console.log("Answer: " + answer);
  newMargin = -(newDistance);
  $cards.first().animate({
    marginLeft: newMargin
  }, speed, function() {
    console.log("animation is done");
  });

}

$('#spin').click(function() {
  $cards.first().css('margin-left', 0);
  spin();
  return false;
});

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

.cardList {
  height: 100px;
  width: 302px;
  position: relative;
  margin: 10px;
  border: 1px solid #33e;
  overflow: hidden;
  white-space: nowrap;
}

.card {
  display: inline-block;
  text-align: center;
  height: 100px;
  width: 100px;
  line-height: 100px;
  background-color: #99e;
  font-family: monospace;
  font-size: 2em;
  color: #444;
  border-left: 1px solid #33e;
  border-right: 1px solid #33e;
}

.cardList::before,
.cardList::after {
  content: '';
  display: block;
  z-index: 100;
  width: 0px;
  height: 0px;
  transform: translateX(-50%);
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
}

.cardList::before {
  position: absolute;
  top: 0px;
  left: 50%;
  border-top: 12px solid #33e;
}

.cardList::after {
  position: absolute;
  bottom: 0px;
  left: 50%;
  border-bottom: 12px solid #33e;
}

div.controls,
button {
  margin: 10px;
  padding: 8px;
  font-family: monospace;
}

div.controls input {
  width: 48px;
  padding: 2px;
  text-align: center;
  font-family: monospace;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="cardList">
  <div class="card" data-id="1">1</div>
  <div class="card" data-id="2">2</div>
  <div class="card" data-id="3">3</div>
  <div class="card" data-id="4">4</div>
  <div class="card" data-id="5">5</div>
  <div class="card" data-id="6">6</div>
  <div class="card" data-id="7">7</div>
  <div class="card" data-id="8">8</div>

</div>
<button id="spin">Spin</button>