我使用以下代码在Wordpress管理员中添加主题选项面板：

<?php

$themename = "Nettuts";
$shortname = "nt";

$categories = get_categories(\'hide_empty=0&orderby=name\');
$wp_cats = array();
foreach ($categories as $category_list ) {
    $wp_cats[$category_list->cat_ID] = $category_list->cat_name;
}
array_unshift($wp_cats, "Choose a category");

$options = array (
    array( "name" => $themename." Options",
    "type" => "title"),

    array( "name" => "General",
    "type" => "section"),
    array( "type" => "open"),

    array( "name" => "Colour Scheme",
    "desc" => "Select the colour scheme for the theme",
    "id" => $shortname."_color_scheme",
    "type" => "select",
    "options" => array("blue", "red", "green"),
    "std" => "blue"),

    array( "name" => "Logo URL",
    "desc" => "Enter the link to your logo image",
    "id" => $shortname."_logo",
    "type" => "text",
    "std" => ""),

    array( "name" => "Custom Option",
    "desc" => "Enter the link to your logo image",
    "id" => $shortname."_custom",
    "type" => "text",
    "std" => ""),

    array( "name" => "Custom CSS",
    "desc" => "Want to add any custom CSS code? Put in here, and the rest is taken care of. This overrides any other stylesheets. eg: a.button{color:green}",
    "id" => $shortname."_custom_css",
    "type" => "textarea",
    "std" => ""),

    array( "type" => "close"),
    array( "name" => "Homepage",
    "type" => "section"),
    array( "type" => "open"),

    array( "name" => "Homepage header image",
    "desc" => "Enter the link to an image used for the homepage header.",
    "id" => $shortname."_header_img",
    "type" => "text",
    "std" => ""),

    array( "name" => "Homepage featured category",
    "desc" => "Choose a category from which featured posts are drawn",
    "id" => $shortname."_feat_cat",
    "type" => "select",
    "options" => $wp_cats,
    "std" => "Choose a category"),

    array( "type" => "close"),
    array( "name" => "Footer",
    "type" => "section"),
    array( "type" => "open"),

    array( "name" => "Footer copyright text",
    "desc" => "Enter text used in the right side of the footer. It can be HTML",
    "id" => $shortname."_footer_text",
    "type" => "text",
    "std" => ""),

    array( "name" => "Google Analytics Code",
    "desc" => "You can paste your Google Analytics or other tracking code in this box. This will be automatically added to the footer.",
    "id" => $shortname."_ga_code",
    "type" => "textarea",
    "std" => ""),

    array( "name" => "Custom Favicon",
    "desc" => "A favicon is a 16x16 pixel icon that represents your site; paste the URL to a .ico image that you want to use as the image",
    "id" => $shortname."_favicon",
    "type" => "text",
    "std" => get_bloginfo(\'url\') ."/favicon.ico"),

    array( "name" => "Feedburner URL",
    "desc" => "Feedburner is a Google service that takes care of your RSS feed. Paste your Feedburner URL here to let readers see it in your website",
    "id" => $shortname."_feedburner",
    "type" => "text",
    "std" => get_bloginfo(\'rss2_url\')),

    array( "type" => "close")

);

function mytheme_add_admin() {
    global $themename, $shortname, $options;

    if ( $_GET[\'page\'] == basename(__FILE__) ) {

        if ( \'save\' == $_REQUEST[\'action\'] ) {

            foreach ($options as $value) {
                update_option( $value[\'id\'], $_REQUEST[ $value[\'id\'] ] ); }

                    foreach ($options as $value) {
                        if( isset( $_REQUEST[ $value[\'id\'] ] ) ) { update_option( $value[\'id\'], $_REQUEST[ $value[\'id\'] ]  ); } else { delete_option( $value[\'id\'] ); } }

                            header("Location: admin.php?page=options.php&saved=true");
die;

        }
        else if( \'reset\' == $_REQUEST[\'action\'] ) {

            foreach ($options as $value) {
                delete_option( $value[\'id\'] ); }

                    header("Location: admin.php?page=options.php&reset=true");
die;

        }

    }

    add_menu_page($themename, $themename, \'administrator\', basename(__FILE__), \'mytheme_admin\');
}

function mytheme_add_init() {
    $file_dir=get_bloginfo(\'template_directory\');
    wp_enqueue_style("functions", $file_dir."/functions/functions.css", false, "1.0", "all");
}

function mytheme_admin() {

    global $themename, $shortname, $options;
    $i=0;

    if ( $_REQUEST[\'saved\'] ) echo \'<div id="message" class="updated fade"><p>\'.$themename.\' settings saved.</p></div>\';
    if ( $_REQUEST[\'reset\'] ) echo \'<div id="message" class="updated fade"><p>\'.$themename.\' settings reset.</p></div>\';

?>
<div class="wrap rm_wrap">
<h2><?php echo $themename; ?> Settings</h2>

<div class="rm_opts">
<form method="post">

<?php foreach ($options as $value) {
    switch ( $value[\'type\'] ) {

    case "open":
?>

<?php break;

case "close":
?>

</div>
</div>
<br />

<?php break;

case "title":
?>
<p>To easily use the <?php echo $themename;?> theme, you can use the menu below.</p>

<?php break;

case \'text\':
?>

<div class="rm_input rm_text">
    <label for="<?php echo $value[\'id\']; ?>"><?php echo $value[\'name\']; ?></label>
    <input name="<?php echo $value[\'id\']; ?>" id="<?php echo $value[\'id\']; ?>" type="<?php echo $value[\'type\']; ?>" value="<?php if ( get_settings( $value[\'id\'] ) != "") { echo stripslashes(get_settings( $value[\'id\'])  ); } else { echo $value[\'std\']; } ?>" />
 <small><?php echo $value[\'desc\']; ?></small><div class="clearfix"></div>

 </div>
<?php
    break;

case \'textarea\':
?>

<div class="rm_input rm_textarea">
    <label for="<?php echo $value[\'id\']; ?>"><?php echo $value[\'name\']; ?></label>
    <textarea name="<?php echo $value[\'id\']; ?>" type="<?php echo $value[\'type\']; ?>" cols="" rows=""><?php if ( get_settings( $value[\'id\'] ) != "") { echo stripslashes(get_settings( $value[\'id\']) ); } else { echo $value[\'std\']; } ?></textarea>
 <small><?php echo $value[\'desc\']; ?></small><div class="clearfix"></div>

 </div>

<?php
    break;

case \'select\':
?>

<div class="rm_input rm_select">
    <label for="<?php echo $value[\'id\']; ?>"><?php echo $value[\'name\']; ?></label>

<select name="<?php echo $value[\'id\']; ?>" id="<?php echo $value[\'id\']; ?>">
<?php foreach ($value[\'options\'] as $option) { ?>
        <option <?php if (get_settings( $value[\'id\'] ) == $option) { echo \'selected="selected"\'; } ?>><?php echo $option; ?></option><?php } ?>
</select>

    <small><?php echo $value[\'desc\']; ?></small><div class="clearfix"></div>
</div>
<?php
    break;

case "checkbox":
?>

<div class="rm_input rm_checkbox">
    <label for="<?php echo $value[\'id\']; ?>"><?php echo $value[\'name\']; ?></label>

<?php if(get_option($value[\'id\'])){ $checked = "checked=\\"checked\\""; }else{ $checked = "";} ?>
<input type="checkbox" name="<?php echo $value[\'id\']; ?>" id="<?php echo $value[\'id\']; ?>" value="true" <?php echo $checked; ?> />

    <small><?php echo $value[\'desc\']; ?></small><div class="clearfix"></div>
 </div>
<?php break;

case "section":

    $i++;

?>

<div class="rm_section">
<div class="rm_title"><h3><?php echo $value[\'name\']; ?></h3><span class="submit"><input name="save<?php echo $i; ?>" type="submit" value="Save changes" />
</span><div class="clearfix"></div></div>
<div class="rm_options">

<?php break;

    }
}
?>

<input type="hidden" name="action" value="save" />
</form>
<form method="post">
<p class="submit">
<input name="reset" type="submit" value="Reset" />
<input type="hidden" name="action" value="reset" />
</p>
</form>
<div style="font-size:9px; margin-bottom:10px;">Icons: <a href="http://www.woothemes.com/2009/09/woofunction/">WooFunction</a></div>
 </div>

<?php
}

?>

<?php
add_action(\'admin_init\', \'mytheme_add_init\');
add_action(\'admin_menu\', \'mytheme_add_admin\');
?>

我搜索了所有的互联网和这个StackExchange网站，但没有找到答案（只有一个，但它是针对“页面”中的自定义写入面板）。

有什么建议吗？