Bootstrap-v5-表单（浮动标签）

一、浮动标签（Floating labels）

1、浮动标签

• .form-floating

<div class="form-floating mb-3">
  <input type="email" class="form-control" id="floatingInput" placeholder="name@example.com">
  <label for="floatingInput">Email address</label>
</div>
<div class="form-floating">
  <input type="password" class="form-control" id="floatingPassword" placeholder="Password">
  <label for="floatingPassword">Password</label>
</div>

2、浮动标签（带值）

• .form-floating
• value

<form class="form-floating">
  <input type="email" class="form-control" id="floatingInputValue" placeholder="name@example.com" value="test@example.com">
  <label for="floatingInputValue">Input with value</label>
</form>

3、浮动标签（带效果）

<form class="form-floating">
  <input type="email" class="form-control is-invalid" id="floatingInputInvalid" placeholder="name@example.com" value="test@example.com">
  <label for="floatingInputInvalid">Invalid input</label>
</form>

二、浮动文本域（Textareas）

1、浮动文本域（基本）

• floatingTextarea

<div class="form-floating">
  <textarea class="form-control" placeholder="Leave a comment here" id="floatingTextarea"></textarea>
  <label for="floatingTextarea">Comments</label>
</div>

2、浮动文本域（自定义高度）

• floatingTextarea
• height

<div class="form-floating">
  <textarea class="form-control" placeholder="Leave a comment here" id="floatingTextarea2" style="height: 100px"></textarea>
  <label for="floatingTextarea2">Comments</label>
</div>

三、浮动选项框（Selects）

1、浮动下拉选项

• floatingSelect

<div class="form-floating">
  <select class="form-select" id="floatingSelect" aria-label="Floating label select example">
    <option selected>Open this select menu</option>
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
  </select>
  <label for="floatingSelect">Works with selects</label>
</div>

四、浮动布局（Layout）

1、浮动文本域和浮动下拉选项一起配合使用

<div class="row g-2">
  <div class="col-md">
    <div class="form-floating">
      <input type="email" class="form-control" id="floatingInputGrid" placeholder="name@example.com" value="mdo@example.com">
      <label for="floatingInputGrid">Email address</label>
    </div>
  </div>
  <div class="col-md">
    <div class="form-floating">
      <select class="form-select" id="floatingSelectGrid" aria-label="Floating label select example">
        <option selected>Open this select menu</option>
        <option value="1">One</option>
        <option value="2">Two</option>
        <option value="3">Three</option>
      </select>
      <label for="floatingSelectGrid">Works with selects</label>
    </div>
  </div>
</div>