javascript - 使用 javascript 中的第 n 个子项指定图像在放置区域的位置

Question

在我的代码中，

我在 class box 中有 four images id box1, box2、box3 和 box4..

每张图片都可以拖放到下面的矩形..

我的问题是当我尝试定位它在dropped area using nth child in css 它不工作

我无法弄清楚 css 中的错误在哪里？

如何使用第 n 个 child 将图像定位在拖放区域上......？如何解决？

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");
console.log(data);
$("#" + data).css("position", "unset");
ev.target.appendChild(document.getElementById(data));
}

body{
background-repeat: no-repeat;
background-size: cover;
width:100%;
height:100%;
overflow: hidden;
background-size: 100vw 100vh;
}
#box1 {
position: absolute;
top: 28.3vh;
left: -10.98vw;
cursor: pointer;
border: 1px solid #0066CC;
background-repeat: no-repeat;
background-size: contain;
}
#box1 p {
width: 10.0vw;
height: 10.0vh;
border-radius: 25%;
}
#box2 {
position: absolute;
top: 13.7vh;
left: -10.98vw;
cursor:pointer;
border:1px solid #0066CC;
background-repeat:no-repeat;
background-size: contain;
}
#box2 p {
width: 5.0vw;
height: 5.0vh;
border-radius: 25%;
}
#box3 {
position: absolute;
top: 7.7vh;
left: 43.98vw;
cursor:pointer;
border:1px solid #0066CC;
background-size: contain;
background-repeat:no-repeat
}
#box3 p {
width: 7.0vw;
height: 7.0vh;
border-radius: 25%;
}
#box4 {
position: absolute;
top: 28.3vh;
left: 40.98vw;
cursor:pointer;
border:1px solid #0066CC;
background-repeat:no-repeat;
background-size:cover;
background-size: contain;
}
#box4 p {
width: 10.0vw;
height: 10.0vh;
border-radius: 25%;
}
.container2 {
width: 50.1vw;
position: fixed;
top: 10.5vh;
left: 30.5vw;
}
.boxright1 p {
font-size: calc(2vw);
height: 4vh;
margin: 0;
color: white;
background-size: cover;
background-repeat:no-repeat;
color: #0066ff;
text-shadow: 0px 0px 0px #999, 0px 0px 0px #888, 0px 0px 0px #777, 0px 0px 0px #6066, 0px 2px 0px #555, 0px 0px 0px #444, 0px 0px 0px #333, 0px 0px 0px #001135;
font:'ChunkFiveRegular';
}
.boxright1 {
position: absolute;
top: 65.3vh;
left: 17.5vw;
width: 61.0vw;
height: 35.0vh;
cursor:pointer;
border:2px solid black;
background-repeat:no-repeat;
background-size: contain;
background-image:url(images/name%20board%20witout%20rope2.png);
background-size: 40vw 55vh; 
}
.boxright1 .box{
position: absolute;
}
.boxright1 .box:nth-child(1) {
top: 0px;
left: 155px;
}
.boxright1 .box:nth-child(2) {
top: 5px;
left:215px;
}
.boxright1 .box:nth-child(3) {
top: 0px;
left: 315px;
}
.boxright1 .box:nth-child(4) {
top: 5px;
left: 415px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p>applying nth child to Class boxright1 not working</p>

<div class="container2">
<div class="containerr">
    <div class="pic" id="content">
        <div id="container">

            <div class="box" id="box1" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300)">
                <p name="values" id="name1" class="hidden"></p>
            </div>

            <div class="box" id="box2" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/g/200/300)">
                <p name="values" id="name2" class="hidden"></p>
            </div>

            <div class="box" id="box3" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300?image=0)">
                <p name="values" id="name3" class="hidden"></p>
            </div>

            <div class="box" id="box4" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300/?gravity=east)">
                <p name="values" id="name4" class="hidden"></p>
            </div>

        </div>
    </div>
</div>
</div>

<div class="boxright1" ondrop="drop(event)" ondragover="allowDrop(event)" id="4" name="d"></div>

Answer 1

第一个问题是你在drop例程中将掉落框的position设置为unset，导致框没有不再被定位。删除该行。

第二个问题是特异性。您首先定位 id，例如 #box1，浏览器将保留为此定义的样式，无论您是否尝试使用 .boxright1 .box:nth-child 覆盖它们(...)。

解决方案不是对原始选择器使用 id，而是使用类名。在下面的解决方案中，我已将 box1 等添加到框的类中，因此您可以使用 .box1 而不是 #box1 然后 .boxright1 .box:nth-child(...) 选择器将覆盖它。

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");
  console.log(data);
  /*$("#" + data).css("position", "unset");*/
  ev.target.appendChild(document.getElementById(data));
}

body {
  background-repeat: no-repeat;
  background-size: cover;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-size: 100vw 100vh;
}

.box1 {
  position: absolute;
  top: 28.3vh;
  left: -10.98vw;
  cursor: pointer;
  border: 1px solid #0066CC;
  background-repeat: no-repeat;
  background-size: contain;
}

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

.box2 {
  position: absolute;
  top: 13.7vh;
  left: -10.98vw;
  cursor: pointer;
  border: 1px solid #0066CC;
  background-repeat: no-repeat;
  background-size: contain;
}

.box2 p {
  width: 5.0vw;
  height: 5.0vh;
  border-radius: 25%;
}

.box3 {
  position: absolute;
  top: 7.7vh;
  left: 43.98vw;
  cursor: pointer;
  border: 1px solid #0066CC;
  background-size: contain;
  background-repeat: no-repeat
}

.box3 p {
  width: 7.0vw;
  height: 7.0vh;
  border-radius: 25%;
}

.box4 {
  position: absolute;
  top: 28.3vh;
  left: 40.98vw;
  cursor: pointer;
  border: 1px solid #0066CC;
  background-repeat: no-repeat;
  background-size: cover;
  background-size: contain;
}

.box4 p {
  width: 10.0vw;
  height: 10.0vh;
  border-radius: 25%;
}

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

.boxright1 p {
  font-size: calc(2vw);
  height: 4vh;
  margin: 0;
  color: white;
  background-size: cover;
  background-repeat: no-repeat;
  color: #0066ff;
  text-shadow: 0px 0px 0px #999, 0px 0px 0px #888, 0px 0px 0px #777, 0px 0px 0px #6066, 0px 2px 0px #555, 0px 0px 0px #444, 0px 0px 0px #333, 0px 0px 0px #001135;
  font: 'ChunkFiveRegular';
}

.boxright1 {
  position: absolute;
  top: 65.3vh;
  left: 17.5vw;
  width: 61.0vw;
  height: 35.0vh;
  cursor: pointer;
  border: 2px solid black;
  background-repeat: no-repeat;
  background-size: contain;
  background-image: url(images/name%20board%20witout%20rope2.png);
  background-size: 40vw 55vh;
}

.boxright1 .box {
  position: absolute;
}

.boxright1 .box:nth-child(1) {
  top: 0px;
  left: 155px;
}

.boxright1 .box:nth-child(2) {
  top: 5px;
  left: 215px;
}

.boxright1 .box:nth-child(3) {
  top: 0px;
  left: 315px;
}

.boxright1 .box:nth-child(4) {
  top: 5px;
  left: 415px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p>applying nth child to Class boxright1 not working</p>

<div class="container2">
  <div class="containerr">
    <div class="pic" id="content">
      <div id="container">

        <div class="box box1" id="box1" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300)">
          <p name="values" id="name1" class="hidden"></p>
        </div>

        <div class="box box2" id="box2" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/g/200/300)">
          <p name="values" id="name2" class="hidden"></p>
        </div>

        <div class="box box3" id="box3" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300?image=0)">
          <p name="values" id="name3" class="hidden"></p>
        </div>

        <div class="box box4" id="box4" draggable="true" ondragstart="drag(event)" style="background-image:url(https://picsum.photos/200/300/?gravity=east)">
          <p name="values" id="name4" class="hidden"></p>
        </div>

      </div>
    </div>
  </div>
</div>

<div class="boxright1" ondrop="drop(event)" ondragover="allowDrop(event)" id="4" name="d"></div>