如何验证WordPress设置API中的单选按钮

我有一个主题，我把它放在一起，允许用户通过单击一个单选按钮来更改样式。我让这个功能在没有验证回调的情况下工作，但在需要验证的选项页面中添加了文本字段。但是现在样式更改单选按钮不能与验证一起工作(如果我不包含验证代码)。看起来Settings API需要对所有东西进行验证。在谷歌上搜索了两天的解决方案后，我找不到任何答案。我试图找出如何验证单选按钮代码或跳过验证仅对单选按钮。以下是相关代码:

<?php
add_action('admin_init', 'mxs_admin_init');
add_action('admin_menu', 'mxs_admin_add_page');
function mxs_admin_add_page() {
    add_theme_page(
        'Mixin&apos; Styles Theme Options',
        'Mixin&apos; Styles Theme Options',
        'manage_options',
        'mixinstyles',
        'mxs_theme_options_page'
        );
    }
function mxs_admin_init() {
    register_setting(
        'mixinstyles_theme_options',
        'mixinstyles_theme_options',
        'mixinstyles_options_validate'
        );
    add_settings_section( // Styles section
        'mixinstyles_main',
        'Mixin&apos; Styles Style Settings',
        'mxs_theming_section_text',
        'mixinstyles'
        );
    add_settings_field(
        'custom_style_buttons',
        '<strong>Color Schemes</strong>',
        'mxs_custom_style_buttons',
        'mixinstyles',
        'mixinstyles_main'
        );
    ...
function mxs_custom_style_buttons() { 
    $options = get_option('mixinstyles_theme_options');
    //var_dump($options); //for debugging
        echo "<div class='radiobutton-wrap'> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='default_style' value='default_style' name='mixinstyles_theme_options[custom_style_buttons]'" . checked( $options['custom_style_buttons'], 1 ) . " /><img src='" . get_bloginfo('template_directory') . "/images/default_screenshot.png' alt='Default style' /><br /><label for='default_style'>Default Style</label> </div> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='blue_orange' value='blue_orange' name='mixinstyles_theme_options[custom_style_buttons]' /><img src='" . get_bloginfo('template_directory') . "/images/blueorange_screenshot.png' alt='Blue/Orange style' /><br /><label for='blue_orange'>Blue/Orange</label> </div> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='violet_yellow' value='violet_yellow' name='mixinstyles_theme_options[custom_style_buttons]' /><img src='" . get_bloginfo('template_directory') . "/images/violetyellow_screenshot.png' alt='Violet/Yellow style' /><br /><label for='violet_yellow'>Violet/Yellow</label> </div> 'n";
        echo "</div> 'n";
        echo "<div class='radiobutton-wrap'> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='magenta_green' value='magenta_green' name='mixinstyles_theme_options[custom_style_buttons]' /><img src='" . get_bloginfo('template_directory') . "/images/magentagreen_screenshot.png' alt='Magenta/Green style' /><br /><label for='magenta_green'>Magenta/Green</label></div> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='orange_blue' value='orange_blue' name='mixinstyles_theme_options[custom_style_buttons]' /><img src='" . get_bloginfo('template_directory') . "/images/orangeblue_screenshot.png' alt='Orange/Blue style' /><br /><label for='orange_blue'>Orange/Blue</label></div> 'n";
        echo "<div class='radiobutton-padding'> 'n <input type='radio' id='yellow_violet' value='yellow_violet' name='mixinstyles_theme_options[custom_style_buttons]' /><img src='" . get_bloginfo('template_directory') . "/images/yellowviolet_screenshot.png' alt='Yellow/Violet style' /><br /><label for='yellow_violet'>Yellow/Violet</label></div> 'n";
        echo "</div> 'n";
    }
    ...
function mxs_style_switcher() {
    global $mixinstyles_theme_options;
    $options = get_option('mixinstyles_theme_options');
        switch ( $options['custom_style_buttons'] ) { //opens switch statement
            case "blue_orange":
                echo '<link rel="stylesheet" href="'; 
                bloginfo('template_directory');
                echo '/custom-styles/blue-orange.css" type="text/css" />' . "'n";
            break;
            case "violet_yellow":
                echo '<link rel="stylesheet" href="';
                bloginfo('template_directory');
                echo '/custom-styles/violet-yellow.css" type="text/css" />' . "'n";
            break;
            case "magenta_green":
                echo '<link rel="stylesheet" href="';
                bloginfo('template_directory');
                echo '/custom-styles/magenta-green.css" type="text/css" />' . "'n";
            break;
            case "orange_blue":
                echo '<link rel="stylesheet" href="';
                bloginfo('template_directory');
                echo '/custom-styles/orange-blue.css" type="text/css" />' . "'n";
            break;
            case "yellow_violet":
            echo '<link rel="stylesheet" href="';
            bloginfo('template_directory');
            echo '/custom-styles/yellow-violet.css" type="text/css" />' . "'n";
            break;
            default:
            echo '';
        } //closes switch statement
}
add_action('wp_head', 'mxs_style_switcher');
...
function mixinstyles_options_validate($input) { //opens mixinstyles_options_validate function
$options = get_option('mixinstyles_theme_options');
//for each radio button
//default
$options['default_style'] = $input['default_style'];
if ( !isset( $input['default_style'] ) ) {
    }
//blue orange
$options['blue_orange'] = $input['blue_orange'];
if ( !isset( $input['blue_orange'] ) ) {
    }
//violet yellow
$options['violet_yellow'] = $input['violet_yellow'];
if ( !isset( $input['violet_yellow'] ) ) {
    }
//magenta green
$options['magenta_green'] = $input['magenta_green'];
if ( !isset( $input['magenta_green'] ) ) {
    }
//orange blue
$options['orange_blue'] = $input['orange_blue'];
if ( !isset( $input['orange_blue'] ) ) {
    }
//yellow violet
$options['yellow_violet'] = $input['yellow_violet'];
if ( !isset( $input['yellow_violet'] ) ) {
    }
return $options;
}
?>

我在函数中对一个复选框进行了类似的验证，如下所示:

//check if checkbox has been checked
$options['remove_blogtitle'] = $input['remove_blogtitle'];
if ( !isset( $input['remove_blogtitle'] ) ) {
    $input['remove_blogtitle'] = null;
    }

我已经尝试了这个与单选按钮，但它不工作