Bootstrap 模态打开时无法获得模糊背景

Question

我正在使用 Bootstrap 5.1.3，我想在模式打开时使用 CSS backdrop-filter 属性来模糊背景。

我尝试过的最简单的方法是：

.modal-backdrop {
  backdrop-filter: blur(5px);
}

现场演示：

https://codepen.io/kikosoft/pen/YzjxOQm

我使用的是最新的 Firefox 浏览器，但在 Chrome (Windows 11) 中结果是相同的。

我尝试了各地建议的许多变体，但没有一个起作用。背景永远不会变得模糊。有人可以用

backdrop-filter

 来模糊背景吗？我在这里缺少什么？

Answer 1

您需要根据以下代码更改 CSS 和 HTML 结构。

---

使用背景滤镜

.modal-open .modal-backdrop {
  backdrop-filter: blur(5px);
  background-color: rgba(0, 0, 0, 0.5);
  opacity: 1 !important;
}

<script src="//cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js"></script>
<link href="//cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet"/>
<h1>This text should get blurred when the modal is opened.</h1>

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-bs-toggle="modal" data-bs-target="#exampleModal">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

---

使用过滤器

.modal-open .main-wrapper {
  filter: blur(5px);
}

<script src="//cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js"></script>
<link href="//cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet"/>
<div class="main-wrapper">
<h1>This text should get blurred when the modal is opened.</h1>

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-bs-toggle="modal" data-bs-target="#exampleModal">
  Launch demo modal
</button>
</div>

<!-- Modal -->
<div class="modal fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

Answer 2

您应该将您的样式应用到

#exampleModal

，如下所示：

#exampleModal {
  backdrop-filter: blur(5px);
}