CSS page-break-before 属性

描述

page-break-before属性指示是否允许在元素框之前出现的分页（以及分页的数量）。

此属性的值并不是确定是否在元素后面插入分页的唯一因素。这个决定还受到前一个元素的page-break-after的值以及任何祖先元素的page-break-inside的值的影响。

可能的值

auto – 强制或者防止在元素框之前出现分页。
always – 在元素框之前强制插入分页。
avoid – 尽量避免在元素框之前插入分页。
left – 在元素框之前强制插入一个或两个分页，以便下一个打印元素的页面是左页。
right – 在元素框之前强制插入一个或两个分页，以便下一个打印元素的页面是右页。

适用于

所有块级元素。

示例

以下是示例 –

<html>
   <head> 

      <style type = "text/css">
         p{page-break-before: always;}
      </style>
   </head>

   <body>

      <p>
         Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies.
         Android offers a unified approach to application development for mobile devices which means developers need only develop for Android, and their applications should be able to run on different devices powered by Android.
         The first beta version of the Android Software Development Kit (SDK) was released by Google in 2007 where as the first commercial version, Android 1.0, was released in September 2008.
         On June 27, 2012, at the Google I/O conference, Google announced the next Android version, 4.1 Jelly Bean. Jelly Bean is an incremental update, with the primary aim of improving the user interface, both in terms of functionality and performance.
         The source code for Android is available under free and open source software licenses. Google publishes most of the code under the Apache License version 2.0 and the rest, Linux kernel changes, under the GNU General Public License version 2
      </p>

      <p>
         Android applications are usually developed in the Java language using the Android Software Development Kit.
         Once developed, Android applications can be packaged easily and sold out either through a store such as Google Play or the Amazon Appstore.
         Android powers hundreds of millions of mobile devices in more than 190 countries around the world. It's the largest installed base of any mobile platform and growing fast. Every day more than 1 million new Android devices are activated worldwide.
         This tutorial has been written with an aim to teach you how to develop and package Android application. We will start from environment setup for Android application programming and then drill down to look into various aspects of Android applications
      </p>

      <button onclick = "myFunction()">Print this page</button>

      <script>
         function myFunction() {
            window.print();
         }
      </script>

   </body>
</html>