Bootstrap-4验证：添加边框和背景色以形成输入组

Question

我有一个使用Bootstrap 4的表单。显示验证错误时，我希望包含input-group（密码）的文本字段能够像上面的文本字段一样将红色边框和背景色应用于整个宽度（用户名）。有没有办法做到这一点？

<div class="form-group">
    <label>Username</label>
    <input class="form-control input-validation-error" type="text" id="Input_UserName" name="Input.UserName" value="">
    <span class="text-danger field-validation-error">Username is a required field</span>
</div>
<div class="form-group">
    <label>Password</label>
    <div class="input-group">
        <input type="password" class="form-control border-right-0 input-validation-error" data-password-input="toggle-password-view" id="Input_Password" name="Input.Password">
        <div class="input-group-append">
            <span class="input-group-text border-left-0 bg-transparent" data-view="toggle-password">
                <span id="password-toggle" class="small">show</span>
            </span>
        </div>
    </div>
    <span class="text-danger field-validation-error">Password is a required field</span>
</div>

Answer 1

让班级input-validation-error成为您的指导...然后检查兄弟姐妹及其子女进行自定义样式

$(document).ready(function() {
  $("input.input-validation-error").css('border', '1px solid red').css('background', 'pink');
  $("input.input-validation-error").siblings('.input-group-append').children('span').css('border', '1px solid red').css('padding', '0');
  $("input.input-validation-error").siblings('.input-group-append').children('span').children('span').css('background', 'pink').css('padding', '.525rem .75rem');
});

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>

<div class="form-group">
  <label>Username</label>
  <input class="form-control input-validation-error" type="text" id="Input_UserName" name="Input.UserName" value="">
  <span class="text-danger field-validation-error">Username is a required field</span>
</div>
<div class="form-group">
  <label>Password</label>
  <div class="input-group">
    <input type="password" class="form-control border-right-0 input-validation-error" data-password-input="toggle-password-view" id="Input_Password" name="Input.Password">
    <div class="input-group-append">
      <span class="input-group-text border-left-0 bg-transparent" data-view="toggle-password">
                <span id="password-toggle" class="small">show</span>
      </span>
    </div>
  </div>
  <span class="text-danger field-validation-error">Password is a required field</span>
</div>

<div class="form-group">
  <label>Password2</label>
  <div class="input-group">
    <input type="password" class="form-control border-right-0 " data-password-input="toggle-password-view" id="Input_Password" name="Input.Password">
    <div class="input-group-append">
      <span class="input-group-text border-left-0 bg-transparent" data-view="toggle-password">
                <span id="password-toggle" class="small">show</span>
      </span>
    </div>
  </div>

</div>