WordPress文章随机缩略图调用的方法

//支持外链缩略图 Edit by laobuluo.com
if ( function_exists(‘add_theme_support’) )
add_theme_support(‘post-thumbnails’);
function catch_first_image()
{
global $post, $posts;$first_img = ”;
ob_start();
ob_end_clean();
$output = preg_match_all(‘//i’, $post->post_content, $matches);
$first_img = $matches [1] [0];
//判断图片是否过小
if(!empty($first_img))
{
$image_size = getimagesize($first_img);
$image_width = $image_size[0];
}
//如果第一张图