拖放时可见性隐藏和可见在javascript中不起作用

Question

我有一个代码，其中有两个box和id box1和box2，

box1和box2可以是dragged and dropped至boxleft，

on dropping background image get deleted，只有name appears in box，

我的问题是

在最初将值加载到box1和box2时，我想隐藏该名称并在将其放到boxleft时显示

如何做到这一点？

var array2 = [];

var items = [{
    label: 'first',
    url: 'https://picsum.photos/200/300?image=0'
  },
  {
    label: 'second',
    url: 'https://picsum.photos/200/300?image=4'
  },
];
var tempimages = [];
array2 = items.slice();
var item;

function rvalue() {
  elements = document.getElementsByClassName("box");

  ptags = document.querySelectorAll('[name="values"]');
  boxtags = document.getElementsByClassName("box");

  for (let index = 0; index < 2; index++) {

    item = array2[index];
    //console.log(item);
    try {

      ptags[index].textContent = item.label;

      ptags[index].dataset.itemLabel = item.url;
      // ptags[index].style.visibility = "hidden";

      boxtags[index].style.backgroundImage = 'url(' + item.url + ')';
    } catch (err) {
      // console.log('Exception');
    }
  }
}

rvalue();


function allowDrop(ev) {
  ev.preventDefault();
}

function drag(ev) {
  ev.dataTransfer.setData("Text", ev.target.id);
}

function drop(ev) {

  ev.preventDefault();
  var data = ev.dataTransfer.getData("text");
  ev.target.appendChild(document.getElementById(data));
  // ptags[index].style.visibility = "visible";
}

#box1 {
  position: absolute;
  top: -10.3vh;
  left: -30.98vw;
  cursor: pointer;
  border: px solid #0066CC;
  background-repeat: no-repeat;
  background-size: cover;
}

#box1 p {
  width: 10.0vw;
  height: 10.0vh;
  border-radius: 25%;
}

#box2 {
  position: absolute;
  top: -10.3vh;
  left: -10.98vw;
  cursor: pointer;
  border: px solid #0066CC;
  background-repeat: no-repeat;
  background-size: cover;
}

#box2 p {
  width: 10.0vw;
  height: 10.0vh;
  border-radius: 25%;
}

.boxleft {
  position: absolute;
  top: 48.3vh;
  left: -25.98vw;
  width: 14.0vw;
  height: 40.0vh;
  cursor: pointer;
  border: 2px solid black;
}

#container {
  white-space: nowrap;
  border: px solid #CC0000;
}

.containerr {
  border: px solid #FF3399;
}

.pic {
  background-size: 100% 100%;
}

.container2 {
  width: 50.1vw;
  position: fixed;
  top: 10.5vh;
  left: 30.5vw;
}

.box p {
  font-size: calc(2vw + 10px);
}

.boxleft p {
  font-size: calc(4vw);
  height: 4vh;
  background: royalblue;
  margin: 0;
  color: white;
}

p {
  font: "Courier New", Courier, monospace;
  font-size: 5vw;
  color: rgba(0, 0, 0, 0.6);
  text-shadow: 2px 8px 6px rgba(0, 0, 0, 0.2), 0px -5px 35px rgba(255, 255, 255, 0.3);
  color: #005ce6;
  text-align: center;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="container2">
  <div class="containerr">
    <div class="pic" id="content">
      <div id="container">
        <div class="box" id="box1">
          <p name="values" draggable="true" draggable="true" ondragstart="drag(event)" id="name1"></p>
        </div>
        <div class="box" id="box2">
          <p name="values" draggable="true" draggable="true" ondragstart="drag(event)" id="name2"></p>
        </div>

      </div>


    </div>
  </div>

<div class="boxleft" ondrop="drop(event)" ondragover="allowDrop(event)" id="2"></div>

Answer 1

我认为您应该拖动<div>而不是<p>，并默认隐藏<p>，这样您的代码将如下所示：

var array2 = [];

var items = [{
    label: 'first',
    url: 'https://picsum.photos/200/300?image=0'
  },
  {
    label: 'second',
    url: 'https://picsum.photos/200/300?image=4'
  },
];
var tempimages = [];
array2 = items.slice();
var item;

function rvalue() {
  elements = document.getElementsByClassName("box");

  ptags = document.querySelectorAll('[name="values"]');
  boxtags = document.getElementsByClassName("box");

  for (let index = 0; index < 2; index++) {

    item = array2[index];
    //console.log(item);
    try {

      ptags[index].textContent = item.label;

      ptags[index].dataset.itemLabel = item.url;
      // ptags[index].style.visibility = "hidden";

      boxtags[index].style.backgroundImage = 'url(' + item.url + ')';
    } catch (err) {
      // console.log('Exception');
    }
  }
}

rvalue();


function allowDrop(ev) {
  ev.preventDefault();
}

function drag(ev) {
  ev.dataTransfer.setData("Text", ev.target.id);
}

function drop(ev) {

  ev.preventDefault();
  var data = ev.dataTransfer.getData("Text");
  var pText = $("#" + data).children()[0].id;
  $("#" + pText).removeClass("hidden");
  ev.target.appendChild(document.getElementById(pText));
  // ptags[index].style.visibility = "visible";
}

#box1 {
  position: absolute;
  top: -10.3vh;
  left: -30.98vw;
  cursor: pointer;
  border: px solid #0066CC;
  background-repeat: no-repeat;
  background-size: cover;
}

#box1 p {
  width: 10.0vw;
  height: 10.0vh;
  border-radius: 25%;
}

#box2 {
  position: absolute;
  top: -10.3vh;
  left: -10.98vw;
  cursor: pointer;
  border: px solid #0066CC;
  background-repeat: no-repeat;
  background-size: cover;
}

#box2 p {
  width: 10.0vw;
  height: 10.0vh;
  border-radius: 25%;
}

.boxleft {
  position: absolute;
  top: 48.3vh;
  left: -25.98vw;
  width: 14.0vw;
  height: 40.0vh;
  cursor: pointer;
  border: 2px solid black;
}

#container {
  white-space: nowrap;
  border: px solid #CC0000;
}

.containerr {
  border: px solid #FF3399;
}

.pic {
  background-size: 100% 100%;
}

.container2 {
  width: 50.1vw;
  position: fixed;
  top: 10.5vh;
  left: 30.5vw;
}

.box p {
  font-size: calc(2vw + 10px);
}

.boxleft p {
  font-size: calc(4vw);
  height: 4vh;
  background: royalblue;
  margin: 0;
  color: white;
}

.hidden{
  visibility: hidden;
}

p {
  font: "Courier New", Courier, monospace;
  font-size: 5vw;
  color: rgba(0, 0, 0, 0.6);
  text-shadow: 2px 8px 6px rgba(0, 0, 0, 0.2), 0px -5px 35px rgba(255, 255, 255, 0.3);
  color: #005ce6;
  text-align: center;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="container2">
  <div class="containerr">
    <div class="pic" id="content">
      <div id="container">
        <div class="box" id="box1" draggable="true" ondragstart="drag(event)">
          <p name="values" id="name1" class="hidden"></p>
        </div>
        <div class="box" id="box2" draggable="true" ondragstart="drag(event)">
          <p name="values" id="name2" class="hidden"></p>
        </div>

      </div>


    </div>
  </div>

<div class="boxleft" ondrop="drop(event)" ondragover="allowDrop(event)" id="2"></div>