复选框默认未选中

Question

对于我的Wordpress插件选项页面，我想使用复选框来设置选项。我正在使用此代码将其添加到选项页面，并且运行良好。除此之外，我希望复选框默认设置为未选中状态。我该怎么做呢？

public function id_number_callback() 
{ 
printf(
'<input id="%1$s" name="cus_func_option[%1$s]" type="checkbox" %2$s" />', 
'add_image_dimesions', 
checked(isset($this->options['add_image_dimesions']), true, false) 
); 

编辑：完整的代码我想用的是这个

class MySettingsPage 
{ 
/** 
* Holds the values to be used in the fields callbacks 
*/ 
private $options; 

/** 
* Start up 
*/ 
public function __construct() 
{ 
    add_action('admin_menu', array($this, 'add_plugin_page')); 
    add_action('admin_init', array($this, 'page_init')); 
} 

/** 
* Add options page 
*/ 
public function add_plugin_page() 
{ 
    // This page will be under "Settings" 
    add_options_page(
     'Settings Admin', 
     'Custom functions', 
     'manage_options', 
     'cus-func-admin', 
     array($this, 'create_admin_page') 
    ); 
} 

/** 
* Options page callback 
*/ 
public function create_admin_page() 
{ 
    // Set class property 
    $this->options = get_option('cus_func_option'); 
?> 
<div class="wrap"> 
    <?php screen_icon(); ?> 
    <h2>Custom Functions</h2>   
    <form method="post" action="options.php"> 
    <?php 
     // This prints out all hidden setting fields 
     settings_fields('cus_func_group'); 
     do_settings_sections('cus-func-admin'); 
     submit_button(); 
    ?> 
    </form> 
</div> 
<?php 
} 

/** 
* Register and add settings 
*/ 
public function page_init() 
{   
    register_setting(
     'cus_func_group', // Option group 
     'cus_func_option', // Option name 
     array($this, 'sanitize') // Sanitize 
    ); 

    add_settings_section(
     'setting_section_id', // ID 
     'Which Custom Functions do you want to use?', // Title 
     array($this, 'print_section_info'), // Callback 
     'cus-func-admin' // Page 
    ); 

    add_settings_field(
     'add_image_dimesions', // ID 
     'Add image dimesions to the Media Page', // Title 
     array($this, 'id_number_callback'), // Callback 
     'cus-func-admin', // Page 
     'setting_section_id' // Section   
    );  

    add_settings_field(
     'title', 
     'Title', 
     array($this, 'title_callback'), 
     'cus-func-admin', 
     'setting_section_id' 
    );  
} 

/** 
* Sanitize each setting field as needed 
* 
* @param array $input Contains all settings fields as array keys 
*/ 
public function sanitize($input) 
{ 
    $new_input = array(); 
    if(isset($input['add_image_dimesions'])) 
     $new_input['add_image_dimesions'] = absint($input['add_image_dimesions']); 

    if(isset($input['title'])) 
     $new_input['title'] = sanitize_text_field($input['title']); 

    return $new_input; 
} 

/** 
* Print the Section text 
*/ 
public function print_section_info() 
{ 
    print 'Pick your Custom Functions below:'; 
} 

/** 
* Get the settings option array and print one of its values 
*/ 
public function id_number_callback() 
{ 


    printf(
     '<input id="%1$s" name="cus_func_option[%1$s]" type="checkbox" %2$s" />', 
'add_image_dimesions', 
checked(isset($this->options['add_image_dimesions']), true, false) 
); 

} 

/** 
* Get the settings option array and print one of its values 
*/ 
public function title_callback() 
{ 


printf(
     '<input id="%1$s" name="cus_func_option[%1$s]" type="checkbox" %2$s />', 
'title', 
checked(isset($this->options['title']), true, false) 
); 


} 
} 

if(is_admin()) 
$my_settings_page = new MySettingsPage(); 

Answer 1

参考WordPress Documentation for checked

什么是isset($this->options['add_image_dimesions'])在你的代码的价值？

这是什么决定它是否被检查。

Answer 2

如果你想在加载页面时，该复选框以总是不被选中，那么你可以删除第二个printf令牌，%2$2，第二个参数的printf，checked(isset($this->options['add_image_dimesions']), true, false)，这将给你：

public function id_number_callback() 
{ 
printf(
'<input id="%1$s" name="cus_func_option[%1$s]" type="checkbox" />', 
'add_image_dimesions' 
);