wordpress调用文章内容中头一张图片

//获取文章首张图片
function catch_that_image() {
global $post, $posts;
$first_img = ”;
ob_start();
ob_end_clean();
$output = preg_match_all(‘//i’, $post->post_content, $matches);
$first_img = $matches [1] [0];
if(empty($first_img)){ //Defines a default image
$first_img = “/images/default.jpg”;}return $first_img;}

function catch_the_image( $id ) {
  // global $post, $posts;
  $first_img = '';
  // 如果设置了缩略图
  $post_thumbnail_id = get_post_thumbnail_id( $id );
  if ( $post_thumbnail_id ) {
    $output = wp_get_attachment_image_src( $post_thumbnail_id, 'large' );
    $first_img = $output[0];
  }
  else { // 没有缩略图，查找文章中的第一幅图片
    ob_start();
    ob_end_clean();
    $output = preg_match_all('//i', $post->post_content, $matches);
    $first_img = $matches [1] [0];
    if(empty($first_img)){ // 既www.111com.net没有缩略图，文中也没有图，设置一幅默认的图片
      $first_img = "/images/default.jpg";
    }
  }
  return $first_img;
}