使用Bootstrap在表单中标记错误

（已通过Bootstrap v4，v3和v3的示例进行了更新）

过去几个主要版本的Bootstrap的带有验证类的表单示例。

Bootstrap v4

在Codepen上查看实时版本

<div class="container">
  <form>
    <div class="form-group row">
      <label for="inputEmail" class="col-sm-2 col-form-label text-success">Email</label>
      <div class="col-sm-7">
        <input type="email" class="form-control is-valid" id="inputEmail" placeholder="Email">
      </div>
    </div>

    <div class="form-group row">
      <label for="inputPassword" class="col-sm-2 col-form-label text-danger">Password</label>
      <div class="col-sm-7">
        <input type="password" class="form-control is-invalid" id="inputPassword" placeholder="Password">
      </div>
      <div class="col-sm-3">
        <small id="passwordHelp" class="text-danger">
          Must be 8-20 characters long.
        </small>      
      </div>
    </div>
  </form>
</div>

Bootstrap v3

在Codepen上查看实时版本

<form role="form">
  <div class="form-group has-warning">
    <label class="control-label" for="inputWarning">Input with warning</label>
    <input type="text" class="form-control" id="inputWarning">
    <span class="help-block">Something may have gone wrong</span>
  </div>
  <div class="form-group has-error">
    <label class="control-label" for="inputError">Input with error</label>
    <input type="text" class="form-control" id="inputError">
    <span class="help-block">Please correct the error</span>
  </div>
  <div class="form-group has-info">
    <label class="control-label" for="inputError">Input with info</label>
    <input type="text" class="form-control" id="inputError">
    <span class="help-block">Username is taken</span>
  </div>
  <div class="form-group has-success">
    <label class="control-label" for="inputSuccess">Input with success</label>
    <input type="text" class="form-control" id="inputSuccess" />
    <span class="help-block">Woohoo!</span>
  </div>
</form>

Bootstrap v2

在jsfiddle上查看实时版本

的.error，.success，.warning和.info类被附加到.control-group。这是v2中的标准Bootstrap标记和样式。只要遵循该步骤，您就可以保持良好状态。当然，如果愿意，您可以按照自己的样式添加弹出窗口或“嵌入式Flash”，但是如果您遵循Bootstrap约定并将这些验证类挂在其上.control-group，它将保持一致且易于管理（至少因为将会继续受益于Bootstrap文档和示例）

  <form class="form-horizontal">
    <div class="control-group warning">
      <label class="control-label" for="inputWarning">Input with warning</label>
      <div class="controls">
        <input type="text" id="inputWarning">
        <span class="help-inline">Something may have gone wrong</span>
      </div>
    </div>
    <div class="control-group error">
      <label class="control-label" for="inputError">Input with error</label>
      <div class="controls">
        <input type="text" id="inputError">
        <span class="help-inline">Please correct the error</span>
      </div>
    </div>
    <div class="control-group info">
      <label class="control-label" for="inputInfo">Input with info</label>
      <div class="controls">
        <input type="text" id="inputInfo">
        <span class="help-inline">Username is taken</span>
      </div>
    </div>
    <div class="control-group success">
      <label class="control-label" for="inputSuccess">Input with success</label>
      <div class="controls">
        <input type="text" id="inputSuccess">
        <span class="help-inline">Woohoo!</span>
      </div>
    </div>
  </form>