很遗憾，您无法控制该页面上加载的文件。。。

但您可以禁用编辑器页面，并为用户提供主题选项，允许用户包含自己的CSS。

为了解决这个问题，如果可能的话，我会自动创建并激活一个子主题：

if(!is_child_theme()){

  require_once(ABSPATH.\'wp-admin/includes/file.php\');
  if(!WP_Filesystem()){
    // fail, proably no write-access, use the parent theme...
  }else{

    $parent = get_theme_data(TEMPLATEPATH.\'/style.css\');
    $name = get_stylesheet().\'-extend\';
    $destination = trailingslashit($GLOBALS[\'wp_filesystem\']->wp_themes_dir()).$name;

    $style = "/*\\n"
            ."Theme Name: {$parent[\'Name\']} - Extend\\n"
            ."Theme URI: {$parent[\'URI\']}\\n"
            ."Description: Automatically generated child theme of {$parent[\'Name\']}. Please leave this one activated for proper customizations to {$parent[\'Name\']}.\\n"
            ."Version: 1.0\\n"
            ."Author: {$parent[\'Author\']}\\n"
            ."Author URI: {$parent[\'AuthorURI\']}\\n"
            ."Template: ".get_template()."\\n"
            ."*/\\n\\n"
            ."/* You can safely edit this file, but keep the Template tag above unchanged! */\\n";

    if(!$GLOBALS[\'wp_filesystem\']->is_dir($destination))
      if($GLOBALS[\'wp_filesystem\']->mkdir($destination, FS_CHMOD_DIR) && $GLOBALS[\'wp_filesystem\']->put_contents($destination.\'/style.css\', $style, FS_CHMOD_FILE)){

        // copy screenshot and license.txt
        $GLOBALS[\'wp_filesystem\']->copy(TEMPLATEPATH.\'/screenshot.png\', $destination.\'/screenshot.png\');
        $GLOBALS[\'wp_filesystem\']->copy(TEMPLATEPATH.\'/license.txt\', $destination.\'/license.txt\');

        switch_theme(get_template(), $name);
        wp_redirect(admin_url("themes.php"));
        die(); // stop execution of the current page
      }else{
        // fail again...
      }
  }
}