这是我的问题的解决方案，供感兴趣的人参考。
在您的功能中包括此功能。php文件
require_once(\'custom/extract-post-thumbnail.php\');
$extract_img = new extract_post_image();
add_filter( \'post_thumbnail_html\', array(&$extract_img, \'get_post_image\'),1,5 );
创建一个新文件并将其命名为“extract post thumbnail.php”，将其放置到名为“custom”的文件夹中，并将其放置在主题功能所在的同一目录中。php文件位于。最后，将下面的代码传递到此文件中。
<?php
class extract_post_image {
public $html;
public $post_id;
public $post_image_id;
public $size;
public $attr;
public function extract_post_image() {
}
public function get_post_image ($html,$post_id, $post_image_id, $size, $attr) {
$this->html = $html;
$this->post_id = $post_id;
$this->post_image_id = $post_image_id;
$this->size = $size;
$this->attr = $attr;
if ($this->html == \'\') {
$this->post_image_id = $this->get_post_image_id ();
if ($this->post_image_id) {
do_action( \'begin_fetch_post_thumbnail_html\', $this->post_id, $this->post_image_id, $this->size );
$this->html = wp_get_attachment_image( $this->post_image_id, $this->size, false, $this->attr );
do_action( \'end_fetch_post_thumbnail_html\', $this->post_id, $this->post_image_id, $this->size );
} else {
$this->html = $this->get_image_in_content ();
}
}
return $this->html;
}
public function get_post_image_id () {
$images = get_children(
array(
\'post_parent\' => $this->post_id,
\'post_status\' => \'inherit\',
\'post_type\' => \'attachment\',
\'post_mime_type\' => \'image\',
\'order\' => \'ASC\',
\'orderby\' => \'menu_order\',
\'numberposts\' => 1
)
);
if ($images) {
foreach ($images as $img) {
$img_id = $img->ID;
}
return $img->ID;
} else {
return NULL;
}
}
public function remote_file_exists($image) {
if ( @file($image)) {
return true;
}
return false;
}
public function get_image_in_content () {
$my_post = get_post($this->post_id);
preg_match_all( \'|<img.*?src=[\\\'"](.*?)[\\\'"].*?>|i\', $my_post->post_content, $matches );
if ( isset( $matches ) ) {
$image = $matches[1][0];
if ( $matches[1][0] && $this->remote_file_exists($image) ) {
$altpattern = \'/alt=([\\\'"])?(.*?)\\\\1/\';
preg_match($altpattern, $matches[0][0], $m);
$alt = $m[2];
$default_attr = array(
\'src\' => $image,
\'class\' => "attachment-$size",
\'alt\' => $alt
);
$this->attr = wp_parse_args($this->attr, $default_attr);
$attr = array_map( \'esc_attr\', $this->attr );
$attributes = \'\';
foreach ( $this->attr as $name => $value ) {
$attributes .= " $name=" . \'"\' . $value . \'"\';
}
$imgwh = getimagesize($image);
$imgsize = image_constrain_size_for_editor($imgwh[0], $imgwh[1], $this->size);
$wh = image_hwstring($imgsize[0], $imgsize[1]);
$this->html = \' <img \'.$attributes.\' \'.$wh.\' />\';
return $this->html;
}
} else {
return NULL;
}
}
}
?>
