Question

我有这段代码

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" type="text/css" media="screen" href="bootstrap/css/bootstrap.min.css" />
    <link rel="stylesheet" type="text/css" media="screen" href="css/styles.css" />
</head>

<body>
    <div class="container">
        <div class="form-wrapper">
            <div class="col-md-6 col-md-offset-3 col-sm-12">
                <div class="form-group">
                    <label for="username">Usuario</label>
                    <input type="text" id="username" class="form-control" />
                </div>
            </div>
            <div class="col-md-6 col-md-offset-3 col-sm-12">
                <div class="form-group">
                    <label for="password">Contraseña</label>
                    <input type="password" id="password" class="form-control" />
                </div>
            </div>
            <div class="col-md-12 text-center">
                <button class="btn btn-primary">Enviar</button>
            </div>
        </div>
    </div>
    <script src="bootstrap/js/bootstrap.min.js"></script>
</body>

</html>

和css

.form-wrapper{
    padding-top: 25%;
    border: 1px solid black;
}

我认为.form-wrapper内容在div中，但是当我添加边框时，这就是结果

我不知道输入是如何在div boders之外的

Answer 1

通过在row内添加container来关注自举规则，问题将得到解决。

顺便说一下，问题只出现在整个宽度上，而且与浮动没有被正确清除有关，即使没有指定填充顶部也会出现

.form-wrapper {
  padding-top: 25%;
  border: 1px solid black;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
  <div class="container">
    <div class="form-wrapper row">
      <div class="col-md-6 col-md-offset-3 col-sm-12">
        <div class="form-group">
          <label for="username">Usuario</label>
          <input type="text" id="username" class="form-control" />
        </div>
      </div>
      <div class="col-md-6 col-md-offset-3 col-sm-12">
        <div class="form-group">
          <label for="password">Contraseña</label>
          <input type="password" id="password" class="form-control" />
        </div>
      </div>
      <div class="col-md-12 text-center">
        <button class="btn btn-primary">Enviar</button>
      </div>
    </div>
  </div>

当添加填充时，div将其内容添加到div之外

1 个答案: