javascript - Bootstrap-4 模态页脚中的可滚动文本区域

Question

我在 Angular-6 项目中使用 Bootstrap-4 模态。对于模态，Modal-Header 是固定高度，Modal-Body 是可滚动的，Modal-Footer 是可变高度但不可滚动。

下面是我的基本 HTML：

/*for debugging purpose*/
.modal {
  display: block !important;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  border-color: #e0e0e7;
  padding: 15px 20px 15px 55px;
  min-height: 70px;
  border-top: 1px solid #e9ecef;
}

.comment-input {
  position: relative;
  width: 100%;
  min-height: 40px;
}

.textarea {
  max-height: 80px;
  overflow: auto;
  width: 100%;
  min-height: 40px;
  padding: 10px 10px 10px 16px;
  word-wrap: break-word;
  line-height: 20px;
}

.textarea:empty:not(:focus)::before {
  content: 'Type your comments here';
  position: absolute;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet" />
<div class="modal" role="dialog">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"></div>
      <div class="modal-body"></div>
      <div class="modal-footer">
        <div class="comment-input">
          <div class="textarea" contenteditable="true"></div>
        </div>
      </div>
    </div>
  </div>
</div>

我试图在插入四行文本后使我的 textarea 可滚动。在插入四行文本之前，modal-footer 应该随着 textarea 的增长而增加其高度。我试图通过上面的 HTML 和 CSS 做同样的事情，但不知何故 modal-footer 并没有因为 textarea 的高度而增加。每一个可能的解决方案将不胜感激。谢谢你。

标签： javascripthtmlcssbootstrap-4

Answer 1

因为modal body你需要max-height与overflow-y: scroll属性一起设置，所以当内容结束时它会滚动max-height。

.modal-body {
  max-height: 200px;
  overflow-y: scroll;
}

则相反modal footer，您需要删除max-height文本区域中的 以及 的overflow:auto属性.textarea

/*for debugging purpose*/

.modal {
  display: block !important;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  border-color: #e0e0e7;
  padding: 15px 20px 15px 55px;
  min-height: 70px;
  border-top: 1px solid #e9ecef;
}

.comment-input {
  position: relative;
  width: 100%;
  min-height: 40px;
}

.textarea {
  width: 100%;
  min-height: 40px;
  padding: 10px 10px 10px 16px;
  word-wrap: break-word;
  line-height: 20px;
}

.textarea:empty:not(:focus)::before {
  content: 'Type your comments here';
  position: absolute;
}

.modal-body {
  max-height: 200px;
  overflow-y: scroll;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet" />
<div class="modal" role="dialog">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"></div>
      <div class="modal-body">
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      </div>
      <div class="modal-footer">
        <div class="comment-input">
          <div class="textarea" contenteditable="true"></div>
        </div>
      </div>
    </div>
  </div>
</div>