我几乎可以正常工作了,但是需要进行改进以适应问题的具体情况,并以不同方式处理附件和帖子类型(请参见代码中的注释)...
首先,我认为应该注意如何找到过滤器:
apply_filters( 'views_' . $screen->id, $views )
foreach( array( 'edit-post', 'edit-page', 'edit-movie', 'upload' ) as $hook )
    add_filter( "views_$hook" , 'wpse_30331_custom_view_count', 10, 1);
function wpse_30331_custom_view_count( $views ) 
{
    global $current_screen;
    switch( $current_screen->id ) 
    {
        case 'edit-post':
            $views = wpse_30331_manipulate_views( 'post', $views );
            break;
        case 'edit-page':
            $views = wpse_30331_manipulate_views( 'page', $views );
            break;
        case 'edit-movie':
            $views = wpse_30331_manipulate_views( 'movie', $views );
            break;
        case 'upload':
            $views = wpse_30331_manipulate_views( 'attachment', $views );
            break;
    }
    return $views;
}
function wpse_30331_manipulate_views( $what, $views )
{
    global $user_ID, $wpdb;
    /*
     * This is not working for me, 'artist' and 'administrator' are passing this condition (?)
     */
    if ( !current_user_can('artist') ) 
        return $views;
    /*
     * This needs refining, and maybe a better method
     * e.g. Attachments have completely different counts 
     */
    $total = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts WHERE (post_status = 'publish' OR post_status = 'draft' OR post_status = 'pending') AND (post_author = '$user_ID'  AND post_type = '$what' ) ");
    $publish = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'publish' AND post_author = '$user_ID' AND post_type = '$what' ");
    $draft = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'draft' AND post_author = '$user_ID' AND post_type = '$what' ");
    $pending = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'pending' AND post_author = '$user_ID' AND post_type = '$what' ");
    /*
     * Only tested with Posts/Pages
     * - there are moments where Draft and Pending shouldn't return any value
     */
    $views['all'] = preg_replace( '/\(.+\)/U', '('.$total.')', $views['all'] ); 
    $views['publish'] = preg_replace( '/\(.+\)/U', '('.$publish.')', $views['publish'] ); 
    $views['draft'] = preg_replace( '/\(.+\)/U', '('.$draft.')', $views['draft'] ); 
    $views['pending'] = preg_replace( '/\(.+\)/U', '('.$pending.')', $views['pending'] ); 
    // Debug info
    //echo 'Default counts: <pre>'.print_r($views,true).'</pre>';
    //echo '<hr><hr>';
    //echo 'Query for this screen of this post_type: <b>'.$what.'</b><pre>'.print_r($wp_query,true).'</pre>';
    return $views;
}
               
              
wp_count_posts过滤器