PHP wordpress-如果特色图片没有'；不存在

这可能是一个重复的问题，但这些类似的问题中没有一个涉及到get_attached_media部分，这正是我需要帮助的地方

如果我在帖子中没有任何特色图片，我想使用贴在帖子内容中的图片作为特色图片

以下是我尝试和失败的地方：

    <article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
  <?php
  if(get_post_thumbnail_id() == TRUE) {
    $image_url = wp_get_attachment_image_src( get_post_thumbnail_id(), 'backstretch' );
  }
  else {
    $image_url = wp_get_attachment_image_src( get_attached_media('image'), 'backstretch');
  }
  ?>
  <header class="backstretch-target backstretch-header <?php echo crisp_filter_img() ?>" data-background="<?php echo $image_url[0]; ?>">

这清楚地表明它以url的形式获取图像属性。我在谷歌上搜索并使用了这些代码，但我就是找不到问题所在

我真的很感谢你的帮助

---

另外，如果你仍然发现这是一个重复，我道歉

嗯，我解决了这个问题。我尝试使用流行的“获取图像”插件，但没有解决我的问题。一天结束时，我扔掉了连接的媒体，并使用了这个功能

函数crisp\u catch\u that\u image（）{
$image\u url=wp\u get\u attachment\u image\u src（get\u post\u thumbnail\u id（），'backstretch'）；
如果（！empty（$image\u url））{
返回$image_url[0]；
}
全球$员额，$员额；
$first_img=''；
ob_start（）；
ob_end_clean（）；
$output=preg_match_all（'//i'，$post->post_content，$matches）；
if（空（$matches[1]））{
返回“”；
}
返回$matches[1][0]；
返回$first\u img；
}

我使用此功能从WordPress帖子中获取所有可用图像：

function get_post_images( $post = null ) {
    if ( $post === null ) {
        global $post;
    }

    /* Get the featured image of the post */
    if ( has_post_thumbnail() ) {
        $images[] = get_post_thumbnail_id( $post->ID );
    }

    /*  If the post contains galleries, get all images from them */
    if( has_shortcode( $post->post_content, 'gallery' ) ) {
        $galleries = get_post_galleries( $post, false );
        foreach ( $galleries as $gallery ) {
            $ids = explode( ',', $gallery['ids'] );
            $images = array_merge( $images, $ids );
        }
    }

    /* Get all single images in the post */
    preg_match_all("/wp-image-(\d+)/", $post->post_content, $imgs );
    foreach ($imgs[1] as $img) {
        $images[] = $img;
    }

    /* get all images attached to the post
     * not sure if this is a good idea, there might be images attached
     * which were not supposed to be published */
    $post_images = get_posts( array(
        'post_parent' => $post->ID,
        'post_type' => 'attachment',
        'numberposts' => -1,
        'post_mime_type' => 'image',
        'exclude' => $images ) );
    foreach ( $post_images as $image ) {
        $images[] = $image->ID;
    }

    /* As a fallback, add a predefined default image */
    if ( sizeof( $images ) == 0 && $this->default_image != null) {
        $images[] = $this->default_image;
    }

    /* remove duplicated images */
    $images = array_unique( $images );

    return $images; 
}

该函数返回一个数组，其中包含与给定帖子相关的所有图像ID，如果您只需要一个，则可以轻松提取：

$images = get_post_images();
echo wp_get_attachment_image( array_shift( $images ) );

function crisp_catch_that_image() {
  $image_url = wp_get_attachment_image_src( get_post_thumbnail_id(), 'backstretch' );
  if (!empty($image_url)) {
    return $image_url[0];
  }
  global $post, $posts;
  $first_img = '';
  ob_start();
  ob_end_clean();
  $output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->post_content, $matches);
  if (empty($matches[1])) {
    return '';
  }
  return $matches[1][0];
  return $first_img;
}

function get_post_images( $post = null ) {
    if ( $post === null ) {
        global $post;
    }

    /* Get the featured image of the post */
    if ( has_post_thumbnail() ) {
        $images[] = get_post_thumbnail_id( $post->ID );
    }

    /*  If the post contains galleries, get all images from them */
    if( has_shortcode( $post->post_content, 'gallery' ) ) {
        $galleries = get_post_galleries( $post, false );
        foreach ( $galleries as $gallery ) {
            $ids = explode( ',', $gallery['ids'] );
            $images = array_merge( $images, $ids );
        }
    }

    /* Get all single images in the post */
    preg_match_all("/wp-image-(\d+)/", $post->post_content, $imgs );
    foreach ($imgs[1] as $img) {
        $images[] = $img;
    }

    /* get all images attached to the post
     * not sure if this is a good idea, there might be images attached
     * which were not supposed to be published */
    $post_images = get_posts( array(
        'post_parent' => $post->ID,
        'post_type' => 'attachment',
        'numberposts' => -1,
        'post_mime_type' => 'image',
        'exclude' => $images ) );
    foreach ( $post_images as $image ) {
        $images[] = $image->ID;
    }

    /* As a fallback, add a predefined default image */
    if ( sizeof( $images ) == 0 && $this->default_image != null) {
        $images[] = $this->default_image;
    }

    /* remove duplicated images */
    $images = array_unique( $images );

    return $images; 
}

$images = get_post_images();
echo wp_get_attachment_image( array_shift( $images ) );