粘滞的标头透明背景

Question

所以对我来说问题是，我希望我的粘性标题div具有透明背景，但仅适用于body标签的背景，以便滚动内容不会通过标题显示。换句话说，因为我的身体标签有背景图像，我想在我的标题中看到它，但不是滚动的内容，我想剪切滚动的内容divs我的标题所在的可见性。我正在使用Bootstrap。对于我的粘性标题我正在使用“position：sticky;”这里描述：https://css-tricks.com/position-sticky-2/

<div style="position: -webkit-sticky; position: sticky; top: 0;">
  <h1 class="text-center">Dictionary</h1>

  <div class="text-center">  
    <% line_size = (@letter_array.length * 5 / 7).ceil %>
    <% (0...line_size).each do | letter | %>
      <form action="<%= "/dictionary/#{@letter_array[letter]}" %>" style="display: inline-block" method="post">
        <input type="hidden" name="_method" value="get" />

        <div>
          <label for="<%= "#{@letter_array[letter]}-link" %>" class="btn" style="padding: 0; margin: 0;"><h4 style="line-height: 0px;"><%= "#{@letter_array[letter].upcase}" %><h4/></label>
          <input id="<%= "#{@letter_array[letter]}-link" %>" type="submit" value="Delete" class="btn btn-link hidden"/>    
        </div>
      </form>
    <% end %>
  </div>

  <div class="text-center">
    <% (line_size...@letter_array.length).each do | letter | %>
      <form action="<%= "/dictionary/#{@letter_array[letter]}" %>" style="display: inline-block" method="post">
        <input type="hidden" name="_method" value="get" />

        <div>
          <label for="<%= "#{@letter_array[letter]}-link" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; margin-left: 0.25em; line-height: normal !important"><h4 style="line-height: 0px;"><%= "#{@letter_array[letter].upcase}" %><h4/></label>
          <input id="<%= "#{@letter_array[letter]}-link" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>    
        </div>
      </form>
    <% end %>
  </div>

  <h5 class="text-center" style="margin-top: 0.25em; margin-bottom: 2em"><a href="<%= "/dictionary/new" %>">Add a New Word to Dictionary</a></h5>
</div>

<% if !@words.nil? %>
  <div class="table-responsive"> 
    <table class="table" style="width: auto !important;" align="center">
      <thead>
        <% word = @words[0] %>
        <tr>
          <td>
            <a href="<%= "/dictionary/#{@letter}/#{word.text}" %>">
              <%= "#{Word.int} - #{word.text}" %>
            </a>
          </td>
          <td>
            <form action="<%= "/dictionary/#{@letter}/#{word.text}/edit" %>" method="post">
              <input type="hidden" name="_method" value="get" />
              <div>
                <label for="<%= "#{word.text}-edit" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-pencil" aria-hidden="true"></i></label>
                <input id="<%= "#{word.text}-edit" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>    
              </div>
            </form>
          </td>
          <td>
            <form action="<%= "/dictionary/#{@letter}/#{word.text}" %>" method="post">
              <input type="hidden" name="_method" value="delete" />
              <div>
                <label for="<%= "#{word.text}-delete" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-trash-o" aria-hidden="true"></i></label>
                <input id="<%= "#{word.text}-delete" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>
              </div>
            </form>
          </td>        
        </tr>
      </thead>
      <tbody id="demo">
        <% @words[1, Word.words_const - 1].each do |word| %>
          <tr>
            <td>
              <a href="<%= "/dictionary/#{@letter}/#{word.text}" %>">
                <%= "#{Word.int} - #{word.text}" %>
              </a>
            </td>
            <td>
              <form action="<%= "/dictionary/#{@letter}/#{word.text}/edit" %>" method="post">
                <input type="hidden" name="_method" value="get" />
                <div>
                  <label for="<%= "#{word.text}-edit" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-pencil" aria-hidden="true"></i></label>
                  <input id="<%= "#{word.text}-edit" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>    
                </div>
              </form>
            </td>
            <td>
              <form action="<%= "/dictionary/#{@letter}/#{word.text}" %>" method="post">
                <input type="hidden" name="_method" value="delete" />
                <div>
                  <label for="<%= "#{word.text}-delete" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-trash-o" aria-hidden="true"></i></label>
                  <input id="<%= "#{word.text}-delete" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>
                </div>
              </form>
            </td>        
          </tr>
        <% end %>


      <!--<% @words.drop(1).each do |word| %>
        <tr>
          <td>
            <a href="<%= "/dictionary/#{@letter}/#{word.text}" %>">
              <%= "#{word.text}" %>
            </a>
          </td>
          <td>
            <form action="<%= "/dictionary/#{@letter}/#{word.text}/edit" %>" method="post">
              <input type="hidden" name="_method" value="get" />
              <div>
                <label for="<%= "#{word.text}-edit" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-pencil" aria-hidden="true"></i></label>
                <input id="<%= "#{word.text}-edit" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>    
              </div>
            </form>
          </td>
          <td>
            <form action="<%= "/dictionary/#{@letter}/#{word.text}" %>" method="post">
              <input type="hidden" name="_method" value="delete" />
              <div>
                <label for="<%= "#{word.text}-delete" %>" class="btn" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"><i class="fa fa-trash-o" aria-hidden="true"></i></label>
                <input id="<%= "#{word.text}-delete" %>" type="submit" value="Delete" class="btn btn-link hidden" style="border: 0; padding: 0; margin-top: -2px; line-height: normal !important"/>
              </div>
            </form>
          </td>        
        </tr>
      <% end %>-->
      </tbody>
    </table>
  </div>
<% end %>


<script>
window.onscroll = function() {scrollFunction()};
var door_key = 1;

function getDocHeight() {
    var D = document;
    return Math.max(
        D.body.scrollHeight, D.documentElement.scrollHeight,
        D.body.offsetHeight, D.documentElement.offsetHeight,
        D.body.clientHeight, D.documentElement.clientHeight
    );
}

function scrollFunction() {
    if (window.pageYOffset + window.outerHeight > getDocHeight() - 100) {
      if (door_key === 1) {
        door_key = 0;
        loadDoc();
      }
    } else {
        door_key = 1;
    }
}

function loadDoc(letter) {
  var xhttp;
  if (window.XMLHttpRequest) {
    // code for modern browsers
    xhttp = new XMLHttpRequest();
    } else {
    // code for IE6, IE5
    xhttp = new ActiveXObject("Microsoft.XMLHTTP");
  }

  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      document.getElementById("demo").innerHTML +=
      this.responseText;
    }
  };
  xhttp.open("GET", "/abc", true);
  xhttp.send();
}
</script>

Answer 1

另一种方法是使用position:fixed代替。使用它会删除文档流中的元素，因此其他元素将会流过，就像它不存在一样。你能做的是添加另一个div，它将作为缺失的固定元素，其高度与固定元素相同，如下所示：

.fixed {
  width: 100%;
  text-align: center;
  position: fixed;
  height: 70px;
  background-color: pink;
}

.solution {
  height: 70px;
}

.content {
  width: 100%;
  height: 300px;
}

<body>
  <div class="fixed">
    <h1>HEADER</h1>
  </div>
  <div class="solution"></div>
  <div class="content">
    Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has
    survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing
    software like Aldus PageMaker including versions of Lorem Ipsum.
  </div>
</body>

没有.solution （用于比较）：

.fixed {
  width: 100%;
  text-align: center;
  position: fixed;
  height: 70px;
  background-color: pink;
}

.content {
  width: 100%;
  height: 300px;
}

<body>
  <div class="fixed">
    <h1>HEADER</h1>
  </div>
  <div class="content">
    Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has
    survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing
    software like Aldus PageMaker including versions of Lorem Ipsum.
  </div>
</body>

Answer 2

在粘贴标题中使用background: transparent;代替背景颜色。

在css-tricks文章中提到的this example中，使用background: transparent;中的dt并根据需要更改颜色和属性。