使用wp_insert_post（）时，如何通过图像URL设置特色图像（缩略图）？

当图像在媒体库中时,可以将其设置为帖子缩略图.要将图像添加到媒体库中,您需要将其上传到服务器. WordPress已经具有将图像放入媒体库的功能,您只需要一个上传文件的脚本即可.

用法:

 Generate_Featured_Image( '../wp-content/my_image.jpg', $post_id );

// $post_id is Numeric ID... You can also get the ID with:
wp_insert_post()
 

功能:

 function Generate_Featured_Image( $image_url, $post_id  ){
    $upload_dir = wp_upload_dir();
    $image_data = file_get_contents($image_url);
    $filename = basename($image_url);
    if(wp_mkdir_p($upload_dir['path']))
      $file = $upload_dir['path'] . '/' . $filename;
    else
      $file = $upload_dir['basedir'] . '/' . $filename;
    file_put_contents($file, $image_data);

    $wp_filetype = wp_check_filetype($filename, null );
    $attachment = array(
        'post_mime_type' => $wp_filetype['type'],
        'post_title' => sanitize_file_name($filename),
        'post_content' => '',
        'post_status' => 'inherit'
    );
    $attach_id = wp_insert_attachment( $attachment, $file, $post_id );
    require_once(ABSPATH . 'wp-admin/includes/image.php');
    $attach_data = wp_generate_attachment_metadata( $attach_id, $file );
    $res1= wp_update_attachment_metadata( $attach_id, $attach_data );
    $res2= set_post_thumbnail( $post_id, $attach_id );
}
 

http://codex.wordpress.org/Function_Reference/wp_upload_dir

http://codex.wordpress.org/Function_Reference/wp_insert_attachment

编辑: 添加了路径创建

http://codex.wordpress.org/Function_Reference/wp_mkdir_p

You can set an image as post thumbnail when it is in your media library. To add an image in your media library you need to upload it to your server. WordPress already has a function for putting images in your media library, you only need a script that uploads your file.

Usage:

Generate_Featured_Image( '../wp-content/my_image.jpg', $post_id );

// $post_id is Numeric ID... You can also get the ID with:
wp_insert_post()

Function:

function Generate_Featured_Image( $image_url, $post_id  ){
    $upload_dir = wp_upload_dir();
    $image_data = file_get_contents($image_url);
    $filename = basename($image_url);
    if(wp_mkdir_p($upload_dir['path']))
      $file = $upload_dir['path'] . '/' . $filename;
    else
      $file = $upload_dir['basedir'] . '/' . $filename;
    file_put_contents($file, $image_data);

    $wp_filetype = wp_check_filetype($filename, null );
    $attachment = array(
        'post_mime_type' => $wp_filetype['type'],
        'post_title' => sanitize_file_name($filename),
        'post_content' => '',
        'post_status' => 'inherit'
    );
    $attach_id = wp_insert_attachment( $attachment, $file, $post_id );
    require_once(ABSPATH . 'wp-admin/includes/image.php');
    $attach_data = wp_generate_attachment_metadata( $attach_id, $file );
    $res1= wp_update_attachment_metadata( $attach_id, $attach_data );
    $res2= set_post_thumbnail( $post_id, $attach_id );
}

http://codex.wordpress.org/Function_Reference/wp_upload_dir

http://codex.wordpress.org/Function_Reference/wp_insert_attachment

EDIT: Added path creation

http://codex.wordpress.org/Function_Reference/wp_mkdir_p

我想通过使用WP核心功能来改善Robs答案 download_url 和 media_handle_sideload

 <?php
/**
* Downloads an image from the specified URL and attaches it to a post as a post thumbnail.
*
* @param string $file    The URL of the image to download.
* @param int    $post_id The post ID the post thumbnail is to be associated with.
* @param string $desc    Optional. Description of the image.
* @return string|WP_Error Attachment ID, WP_Error object otherwise.
*/
function Generate_Featured_Image( $file, $post_id, $desc ){
    // Set variables for storage, fix file filename for query strings.
    preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );
    if ( ! $matches ) {
         return new WP_Error( 'image_sideload_failed', __( 'Invalid image URL' ) );
    }

    $file_array = array();
    $file_array['name'] = basename( $matches[0] );

    // Download file to temp location.
    $file_array['tmp_name'] = download_url( $file );

    // If error storing temporarily, return the error.
    if ( is_wp_error( $file_array['tmp_name'] ) ) {
        return $file_array['tmp_name'];
    }

    // Do the validation and storage stuff.
    $id = media_handle_sideload( $file_array, $post_id, $desc );

    // If error storing permanently, unlink.
    if ( is_wp_error( $id ) ) {
        @unlink( $file_array['tmp_name'] );
        return $id;
    }
    return set_post_thumbnail( $post_id, $id );

}
 

I'd like to improve Robs answer by utilizing the WP core functions download_url and media_handle_sideload

<?php
/**
* Downloads an image from the specified URL and attaches it to a post as a post thumbnail.
*
* @param string $file    The URL of the image to download.
* @param int    $post_id The post ID the post thumbnail is to be associated with.
* @param string $desc    Optional. Description of the image.
* @return string|WP_Error Attachment ID, WP_Error object otherwise.
*/
function Generate_Featured_Image( $file, $post_id, $desc ){
    // Set variables for storage, fix file filename for query strings.
    preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );
    if ( ! $matches ) {
         return new WP_Error( 'image_sideload_failed', __( 'Invalid image URL' ) );
    }

    $file_array = array();
    $file_array['name'] = basename( $matches[0] );

    // Download file to temp location.
    $file_array['tmp_name'] = download_url( $file );

    // If error storing temporarily, return the error.
    if ( is_wp_error( $file_array['tmp_name'] ) ) {
        return $file_array['tmp_name'];
    }

    // Do the validation and storage stuff.
    $id = media_handle_sideload( $file_array, $post_id, $desc );

    // If error storing permanently, unlink.
    if ( is_wp_error( $id ) ) {
        @unlink( $file_array['tmp_name'] );
        return $id;
    }
    return set_post_thumbnail( $post_id, $id );

}

尝试使用 set_post_thumbnail() .

Otto编辑:您已澄清您的问题,因此我将澄清Chip给予的答复.

基本上,您还需要为帖子添加"附件".当图像上传到WordPress媒体库中时,会为其添加一个特殊的帖子条目,并带有附件的帖子类型.该附件通过post_parent标识符链接到某些特定的帖子.

因此,如果您知道附件的ID,则使用发布对象或ID和附件ID调用set_post_thumbnail只需设置发布缩略图标志.

如果尚未创建附件,则需要先执行该操作.最简单的方法是使用 wp_insert_attachment() .此函数采用一些参数组成的数组,文件名(文件必须已经在正确的上载目录中)以及要将附件附加到的父帖子的帖子ID.

仅将文件上传并附加到帖子不会自动执行任何操作.这只是一种分类机制.例如,画廊机制使用帖子的附加图像来构建该帖子的[图库].帖子的缩略图只是已设置为缩略图的附件图像之一.

有关如何使用wp_insert_attachment的更多信息,请参见法典(上面链接).

Try using set_post_thumbnail().

Edit by Otto: You clarified your question, so I'll clarify the response Chip gave.

Basically, you need to make the 'attachment' for the post as well. When an image is uploaded into the WordPress media library, a special post entry is made for it with a post type of attachment. This attachment is linked to some specific post via the post_parent identifier.

So if you know the ID of the attachment, then calling set_post_thumbnail with the post object or ID and the attachment ID will simply set the post thumbnail flag.

If you have not created the attachment yet, then you will need to do that first. Easiest way to do that is with wp_insert_attachment(). This function takes an array of a few parameters, the filename (the file must already be in the proper uploads directory), and the post ID of the parent post that you want to attach the attachment to.

Just having a file uploaded and attached to a post doesn't do anything automatically. This is simply a sort of categorization mechanism. The gallery mechanism, for example, uses the attached images of a post to build the [gallery] for that post. A thumbnail for a post is just one of the attached images which has be set to be the thumbnail.

More info on how to use wp_insert_attachment can be found in the codex (linked above).

set_post_thumbnail() 是满足此要求的最佳功能.

我认为,您可以通过 get_children() <找到附件的ID/a>或 get_posts() .结果有一个数组,该数组内部是ID.以下示例进行测试；我希望它能起作用；无需测试即可写作,只能从头开始.

对于您的要求,重要的是,您要使用post-ID更改post-ID；返回附件的ID,这样您就可以使用set_post_thumbnail().

 $attachments = get_children( 
    array(
        'post_parent' => get_the_ID(), 
        'post_type' => 'attachment', 
        'post_mime_type' => 'image'
    )
);
foreach ( $attachments as $attachment_id => $attachment ) {
    echo wp_get_attachment_image($attachment_id);
}
 

set_post_thumbnail() is the best function for this requirement.

I think, you find the ID of an attachment via get_children() or get_posts(). The result have an array and inside this array is the ID. The follow example for testing; i hope it works; write without tests, only on scratch.

For your requirement it is important, that you change get_the_ID() with your post-ID; return the ID of the Attachment and this can you use foth set_post_thumbnail().

$attachments = get_children( 
    array(
        'post_parent' => get_the_ID(), 
        'post_type' => 'attachment', 
        'post_mime_type' => 'image'
    )
);
foreach ( $attachments as $attachment_id => $attachment ) {
    echo wp_get_attachment_image($attachment_id);
}

只是发现了这一点,并使其变得更加简单,有效,但我不是安全检查器

 if(!empty($_FILES)){
    require_once( ABSPATH . 'wp-admin/includes/post.php' );
    require_once( ABSPATH . 'wp-admin/includes/image.php' );
    require_once( ABSPATH . 'wp-admin/includes/file.php' );
    require_once( ABSPATH . 'wp-admin/includes/media.php' );

    $post_ID = "your post id!";

    $attachment_id = media_handle_upload( 'file', $post_ID );
    set_post_thumbnail( $post_ID, $attachment_id );
}
 

简单还是什么?获取正确的文件后,wordpress将处理媒体并上传,然后将其设置为缩略图.

Just found this and made it much simpler, works but I'm no security scrubber

if(!empty($_FILES)){
    require_once( ABSPATH . 'wp-admin/includes/post.php' );
    require_once( ABSPATH . 'wp-admin/includes/image.php' );
    require_once( ABSPATH . 'wp-admin/includes/file.php' );
    require_once( ABSPATH . 'wp-admin/includes/media.php' );

    $post_ID = "your post id!";

    $attachment_id = media_handle_upload( 'file', $post_ID );
    set_post_thumbnail( $post_ID, $attachment_id );
}

simple or what? after getting the right files, wordpress will handle the media and upload it, then set it as a thumbnail.