将绝对定位的div扩展并定位到相对定位的父对象

Question

关于相似主题的许多问题已被回答，但是我在任何地方都找不到该问题的确切答案。 另外，考虑到现在是2018年，我想知道是否有任何新方法可以实现我想要的目标。

基本上，我的<div>内容超出了高度，因此需要滚动。 在<div>是等待或加载模式，该模式在下载新数据时将其覆盖。 除非用户向下滚动，并且绝对定位的div（固定为100％）固定在内容的顶部，否则它会正常工作。

我尝试过使用top和bottom以及多个position并为父母和孩子display变化，但是没有运气。

以下是具有所有相关代码的jsfiddle： https ://jsfiddle.net/wmu7ghmm/2/。

有任何想法吗？

Answer 1

只需使用户滚动到顶部即可。

HTML

<div class="container" id="container">
 <div id="wait-modal" class="waiting" style="display:none"></div>

  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  <p>This is a bunch of text, over and over again.<p>
  </div>

 <br>

 <button onclick="document.getElementById('wait-modal').style.display='block';document.getElementById('container').classList.add('no-scroll');document.getElementById('container').scrollTo({top:0})">
   Load Data
 </button>

CSS

.container {
  width:300px;
  height:300px;
  max-height:300px;  
  overflow-y:scroll;
  background-color:#dedede;
  position:relative;
}
.container.no-scroll {
  overflow: hidden;
}

.waiting {
  position:absolute;
  height:100%;
  width:100%;
  color:white;
  text-align:center;
  padding-top:20px;

  background-color:rgba(0,0,0,0.5);
  transition:background-color 250ms ease;


}

.waiting:hover {
  background-color:rgba(0,0,0,0.35);
  transition:background-color 250ms ease;
}
.waiting:after {
  content:'PLEASE WAIT...';
  font-size:30px;
}

Answer 2

只需将其从容器中取出并以与容器完全相同的尺寸将其绝对定位在容器上即可。

.waiting {
  position:absolute;
  z-index:10;
  width:300px;
  height:300px;
  max-height:300px;  
  color:white;
  text-align:center;
  padding-top:20px;

  background-color:rgba(0,0,0,0.5);
  transition:background-color 250ms ease; 
}

https://jsfiddle.net/wmu7ghmm/4/