Question

我是PHP和Bootstrap的新手。我正在制作一个登录表单，当我不将<link rel="stylesheet" type="text/css" href="styles.css">放在标题中时，该表单非常好。

但是我不能只从标题中删除它们，因为某些自定义按钮等以后会需要它们。

在下面查看此代码段。如您所见，当我已经指示mt-5时，会有一个空格。知道是什么原因造成的，如何解决？预先感谢！

[！[在此处输入图片描述] [1]] [1]

.index-banner {
  background: linear-gradient(rgba(0, 0, 50, 0.5), rgba(0, 0, 40, 0.5)), url(images/1.jpg) no-repeat center center fixed;
  background-size: cover;
}

.primary-container {
  padding-top: 150px;
  padding-left: 50px;
  transition: all 4s ease-in-out;
  line-height: 10px;
}

<?php require_once 'indexheader.php'; ?>

<!DOCTYPE html>
<html>

<head>
  <title>Leafnote | Register</title>

  <link rel="stylesheet" type="text/css" href="styles.css">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/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>
</head>

<body>
  <div class="container">
    <div class="row">
      <div class="col-lg-4 m-auto">
        <div class="card bg-white mt-5">
          <div class="card-title text-black">
            <h5 class="text-center py-2 font-weight-bold">Register</h5>
          </div>
          <div class="card-body">
            <form action="process.php" method="POST">
              <input type="text" name="lname" placeholder="Lastname" class="form-control mb-2">
              <input type="text" name="fname" placeholder="Firstname" class="form-control mb-2">
              <input type="text" name="email" placeholder="Email address" class="form-control mb-2">
              <input type="text" name="passw" placeholder="Password" class="form-control mb-2">
              <input type="text" name="passw2" placeholder="Re-enter password" class="form-control mb-2">
              <button class="btn btn-success btn-block mt-3" name="register" class="pt-3">Register</button>

              <div class="text-center mt-3" style="font-size: 14px;">Already have an account?
                <a href="signup.php" class="alert-link">Login</a>
              </div>
            </form>
          </div>
        </div>
      </div>
    </div>
  </div>
  </div>
</body>

</html>

Answer 1

实际上，空白来自margin-bottom类中的card-title，而padding类中的card-body来自引导卡中默认提供的空白。只需将其添加到您的css文件中即可覆盖引导css

.card-title {
    margin-bottom: 0 !important;
}

.card-body {
    padding-top: 0 !important;
}

Answer 2

Bootstrap提供实用程序类，这些类非常方便，并减少了额外的CSS，例如添加padding或margin等。

无论何时需要添加或删除边距，都可以添加类，就像使用填充一样

mb-0 , mb-10

您可以获得更多信息 Bootstrap Utilities

Answer 3

将其添加到样式表，即style.css

.card-body{
    padding: 0 24px;
}

.card-title{
    margin:0
}

Answer 4

不需要额外的CSS，因为有Bootstrap4类可以消除多余的填充和边距。您可以使用mb-0删除margin-bottom。您可以了解有关Spacing in Bootstrap 4

的更多信息

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.1.0/css/all.css" integrity="sha384-lKuwvrZot6UHsBSfcMvOkWwlCMgc0TaWr+30HWe3a4ltaBwTZhyTEggF5tJv8tbt" crossorigin="anonymous">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/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>
</head>
<body>
  <div class="container">
    <div class="row">
      <div class="col-lg-4 m-auto">
        <div class="card bg-white mt-5">
          <div class="card-title text-black mb-0">
            <h5 class="text-center py-2 font-weight-bold mb-0">Register</h5>
          </div>
          <div class="card-body">
            <form action="process.php" method="POST">
              <input type="text" name="lname" placeholder="Lastname" class="form-control mb-2">
              <input type="text" name="fname" placeholder="Firstname" class="form-control mb-2">
              <input type="text" name="email" placeholder="Email address" class="form-control mb-2">
              <input type="text" name="passw" placeholder="Password" class="form-control mb-2">
              <input type="text" name="passw2" placeholder="Re-enter password" class="form-control mb-2">
              <button class="btn btn-success btn-block mt-3" name="register" class="pt-3">Register</button>
              <div class="text-center mt-3" style="font-size: 14px;">Already have an account?
                <a href="signup.php" class="alert-link">Login</a>
              </div>
            </form>
          </div>
        </div>
      </div>
    </div>
  </div>
</body>
   </html>

使用Bootstrap 4，我的卡标题底部显示了额外的空白

4 个答案: