我找到了@toscho 非常有用，但由于我有多个选项要添加，所以我对代码进行了一些修改，以便我所要做的就是创建一个简单的扩展类，其中包含几个选项。
我还发现将选项简单地添加到列表的末尾很不方便，因此我添加了一个“position”参数，允许您选择这些选项中的任何一个-
\'first\' - 在第一次设置（当前位置）之前\'last\'- 上次设置（当前背景色）后Integer position - 要在前面插入设置的行号（必须是整数）
以下是代码-
add_action(\'load-appearance_page_custom-background\', array(\'PS_Background_Setting_Random\', \'get_instance\'));
add_action(\'load-appearance_page_custom-background\', array(\'PS_Background_Setting_Position_Y\', \'get_instance\'));
add_action(\'load-appearance_page_custom-background\', array(\'PS_Background_Setting_Size\', \'get_instance\'));
/**
* Add a new \'Random Background\' setting to the Customise Background admin page
*/
final class PS_Background_Setting_Random extends PS_Background_Setting{
/**
* The main instance
*
* @var object|null
*/
protected static $instance = null;
/**
* Return an instance of this class
*
* @return object An instance of this class
*/
public static function get_instance(){
NULL === self::$instance and self::$instance = new self;
return self::$instance;
}
/**
* Constructor
*/
public function __construct(){
$args = array(
\'mod\' => \'ps_background_random\',
\'default\' => \'yes\',
\'label\' => __(\'Random Background\', \'djg_photo_show\'),
\'position\' => \'first\',
\'options\' => array(
\'yes\' => __(\'Yes\', \'djg_photo_show\'),
\'no\' => __(\'No\', \'djg_photo_show\')
)
);
parent::__construct($args);
}
}
/**
* Add a new \'Background Position (Y)\' setting to the Customise Background admin page
*/
final class PS_Background_Setting_Position_Y extends PS_Background_Setting{
/**
* The main instance
*
* @var object|null
*/
protected static $instance = null;
/**
* Return an instance of this class
*
* @return object An instance of this class
*/
public static function get_instance(){
NULL === self::$instance and self::$instance = new self;
return self::$instance;
}
/**
* Constructor
*/
public function __construct(){
$args = array(
\'mod\' => \'ps_background_position_y\',
\'default\' => \'cover\',
\'label\' => __(\'Position (Y)\', \'djg_photo_show\'),
\'position\' => 3,
\'options\' => array(
\'top\' => __(\'Top\', \'djg_photo_show\'),
\'center\' => __(\'Centre\', \'djg_photo_show\'),
\'bottom\' => __(\'Bottom\', \'djg_photo_show\')
)
);
parent::__construct($args);
}
}
/**
* Add a new \'Background Size\' setting to the Customise Background admin page
*/
final class PS_Background_Setting_Size extends PS_Background_Setting{
/**
* The main instance
*
* @var object|null
*/
protected static $instance = null;
/**
* Return an instance of this class
*
* @return object An instance of this class
*/
public static function get_instance(){
NULL === self::$instance and self::$instance = new self;
return self::$instance;
}
/**
* Constructor
*/
public function __construct(){
$args = array(
\'mod\' => \'ps_background_size\',
\'default\' => \'cover\',
\'label\' => __(\'Size\', \'djg_photo_show\'),
\'position\' => 6,
\'options\' => array(
\'auto\' => __(\'Auto\', \'djg_photo_show\'),
\'contain\' => __(\'Contain\', \'djg_photo_show\'),
\'cover\' => __(\'Cover\', \'djg_photo_show\')
)
);
parent::__construct($args);
}
}
/**
* Add a new setting to the Customise Background admin page
*/
class PS_Background_Setting{
/**
* The name for the theme modification option
*
* @var string
*/
private $mod = \'\';
/**
* The default value to return if $mod is not yet set
*
* @var mixed
*/
private $default = false;
/**
* The label for the additional setting
*
* @var string
*/
private $label = \'\';
/**
* The options to use for creating the fields for the additional setting
*
* @var array
*/
private $options = array();
/**
* The nonce for the additional setting
*
* @var string
*/
private $nonce;
/**
* The HTML fields for all of the options for the additional setting
*
* @var string
*/
private $fields;
/**
* The position in which to insert the option
*
* @var string
*/
private $position = \'last\';
/**
* Constructor
*/
public function __construct($args = array()){
/** Map the args to this object */
foreach($args as $key => $value) :
$this->$key = $value;
endforeach;
/** Ensure that all of the required $args are valid */
if(!$this->is_valid_args()) :
return;
endif;
add_action(\'admin_footer-appearance_page_custom-background\', array($this, \'output_additional_setting\'));
/** Check to see if there is an option to save */
if(!empty($_POST[$this->mod])):
/** Check the nonce is valid and save the updated setting */
check_admin_referer($this->mod, "_ps_nonce-$this->mod");
set_theme_mod($this->mod, $_POST[$this->mod]);
endif;
}
/**
* Ensure that all of the required $args are valid
*/
private function is_valid_args(){
return (empty($this->mod) || empty($this->label) || empty($this->options)) ? false : true;
}
/**
* Output the additional custom fields to the custom backgrounds page
*/
public function output_additional_setting(){
$this->nonce = wp_nonce_field( // Create a nonce for each settings so that it can be checked when the user saves
$this->mod, // The nonce $action
"_ps_nonce-$this->mod", // The nonce $name
true, // Also create a referer nonce
false // Do not echo
);
$this->set_fields(); // Set up the fields for this setting
$this->print_script(); // Print the jQuery that will insert the setting into the DOM
}
/**
* Create the HTML fileds for all of the options required for the additional setting
*
* @return string The fields for the additional setting
*/
private function set_fields(){
$saved_value = get_theme_mod($this->mod, $this->default);
foreach($this->options as $value => $description) :
$checked = ($value === $saved_value) ? \'checked="true"\' : false;
$fields[] = sprintf(
\'<label>\'.
\'<input type="radio" id="%1$s" name="%2$s" value="%3$s" %4$s>\'.
\'%5$s</label> \',
"$this->mod-$key", /** %1$s - The option ID */
$this->mod, /** %2$s - The option name */
$value, /** %3$s - The option vale */
$checked, /** %4$s - Whether or not the option should be checked */
$description /** %5$s - The option description */
);
endforeach;
$this->fields = join(\'\', $fields);
}
/**
* Create the $row to insert in to the DOM and the jQuery function to carry out the insertion
*/
private function print_script(){
$row = sprintf(
\'<tr>\'.
\'<th scope="row">%1$s</th>\'.
\'<td><fieldset>\'.
\'<legend class="screen-reader-text"><span>Background %1$s</span></legend>\'.
\'%2$s%3$s</fieldset></td></tr>\',
$this->label, /** %1$s - The setting label */
$this->nonce, /** %2$s - The nonce field for this setting */
$this->fields /** %3$s - The setting fields */
);
if(!is_int($this->position)) :
$this->position = (in_array($this->position, array(\'first\', \'last\'))) ? $this->position : \'last\';
endif;
?>
<script id="custom-background-mod-<?php echo $this->mod; ?>">jQuery(function <?php echo $this->mod; ?>($){
/** Insert the \'<?php echo $this->mod; ?>\' setting option in to the Custom Background admin page */
var row = \'<?php echo $row; ?>\';
var rows = $(\'.form-table:last tr\');
<?php if(is_int($this->position)) : ?>
var position = parseInt(\'<?php echo $this->position; ?>\');
if(position < 0){
rows.first().before(row);
}
else if(position > rows.length){
rows.last().after(row);
}
else{
rows.eq(position - 1).before(row);
}
<?php elseif($this->position === \'first\') : ?>
$(\'.form-table:last tr:first\').before(row);
<?php else : ?>
$(\'.form-table:last tr:last\').after(row);
<?php endif; ?>
});</script>
<?php
}
}
