如何使用javascript中的第n个孩子在丢弃区域上定位图像

Question

我有four images在class box有id box1 ， box2 ， box3和box4 ..

each image都可以dragged and dropped到下面的rectangle ..

我的问题是当我try to position使用css nth child try to position它放置在dropped area it is not working

在css中发生错误的地方在哪里？

如何使用第n个孩子在丢弃区域上定位图像..

 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: px 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:px 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:px 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:px 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 0 px 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

所以基本上你的错误是你忘记了. 在你的CSS中选择一个类

所以代替（选择元素<box> ）

.boxright1 box:nth-child(1) {

它应该是（选择class="box" ）

.boxright1 .box:nth-child(1) {

并将！important添加到您的nth-child top和left值，以使其覆盖初始的#box_x值

但通常你应该使用一些更优雅的方法，如（flex）网格或某事

Answer 2

您已经将#box1设置为absolute位置。 所以里面.boxright1掉落区域nth-child不工作。 所以你可以改变

#box1 {
  position: absolute;
  ...
}

变成

#container .box:nth-child(1) { 
  position: absolute;
  ....
  ....
}

现在，您尝试使用nth child定位在dropped area

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

查看演示

body{

background-repeat: no-repeat;
 background-size: cover;
 width:100%;
 height:100%;
  overflow: hidden;
   background-size: 100vw 100vh;
}
#container .box:nth-child(1) { 
  position: absolute;
  top: 1.3vh;
  left: -10.8vw;
  cursor: pointer;
  border: px solid #0066CC;
  background-repeat: no-repeat;
  background-size: contain;
}

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


#container .box:nth-child(2) {  
  position: absolute;
  top: 13.7vh;
  left: -10.98vw;

  cursor:pointer;
  border:px solid #0066CC;
  background-repeat:no-repeat;
  background-size: contain;
}

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

#container .box:nth-child(3) {
  position: absolute;
  top: 7.7vh;
  left: 43.98vw;

  cursor:pointer;
  border:px solid #0066CC;
  background-size: contain;
  background-repeat:no-repeat;


}

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

#container .box:nth-child(4) {
  position: absolute;
  top: 28.3vh;
  left: 40.98vw;

  cursor:pointer;
  border:px 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 0
    px 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 !important;
  background-size: contain;
}
.boxright1 .box:nth-child(1) {
    top: 0px;
    left: 0px;
}
.boxright1 .box:nth-child(2) {
    top: 5px;
    left:140px;
}
.boxright1 .box:nth-child(3) {
    top: 125px;
    left: 50px;

}
.boxright1 .box:nth-child(4) {
    top: 145px;
    left: 145px;
}

Answer 3

当我查看.boxright1 drop容器中的元素检查器时，我看到.box元素上有内联样式。

element.style {
    background-image: url(https://picsum.photos/200/300);
    position: unset;
}

看起来你放弃它们后，你会在元素上取消JS中的值。

$("#"+data).css("position","unset");

由于position未unset ，因此top和left值不再有任何意义。

如果您可以删除该position: unset ，则元素将遵循您设置的top和left属性，并相对于放置容器定位。