CSS - page-break-before

page-break-before 屬性指示在元素框之前是否（以及有多少）允許分頁符。

此屬性的值並非決定是否應在元素後進行分頁符的唯一因素。此決定還將受到前面元素的 page-break-after 值以及任何祖先元素的 page-break-inside 值的影響。

可能的值

auto − 在元素框之前不強制也不阻止分頁符。
always − 在此元素框之前強制分頁符。
avoid − 儘可能不在元素框之前放置分頁符。
left − 在元素框之前強制一頁或兩頁分頁符，以便列印元素的下一頁為左頁。
right − 在元素框之前強制一頁或兩頁分頁符，以便列印元素的下一頁為右頁。

應用於

所有塊級元素。

示例

這是一個示例：

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

   <body>
   
      <p>
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         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>
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      </p>
      
      <button onclick = "myFunction()">Print this page</button>
      
      <script>
         function myFunction() {
            window.print();
         }
      </script>
      
   </body>
</html>

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