PHP/CSS 随机背景

Question

尝试在两张图片之间获取随机背景。

PHP(在 index.php 中的 Doctype 之前):

<?php
$bg = array('back1.jpg', 'back2.jpg' ); // array of filenames
$i = rand(0, count($bg)-1); // generate random number size of the array
$selectedBg = "$bg[$i]"; // set variable equal to which random filename was chosen
?>

CSS:

body {
  height: 100%;
  margin: 0;
  color: #474747;
  font: 13px/23px  'Exo 2', sans-serif;
  min-width: 1186px;
  background: url( ../img/<?php echo $selectedBg; ?>) no-repeat 50% 50%;
  background-size: cover;
  background-attachment: fixed;
}

问题是没有为任何一个图像设置背景!

编辑:

我已经转向了一个完整的 PHP 方法，尽管它有错误:

Line : 5,   Error type : 4
Message : syntax error, unexpected '(', expecting variable (T_VARIABLE) or '$'

代码:

<?php
  $bg = array('back1.jpg', 'back2.jpg' ); // array of filenames
  $i = rand(0, count($bg)-1); // generate random number size of the array
  $selectedBg = "$bg[$i]"; // set variable equal to which random filename was   chosen
  $('body').css( {                        'background-image': 'url( img / ' +     echo $selectedBg + ')'            } );
?>

Answer 1

你要找的是

array_rand();

PHP 手册:http://php.net/manual/en/function.array-rand.php

对于您的 PHP:

<?php
$bg = array('back1.jpg', 'back2.jpg' ); // array of filenames
$i = array_rand($bg); // generate random number size of the array
$selectedBg = $bg[$i]; // set variable equal to which random filename was chosen
?>