我們假設 github 的網站上這個 js 檔案永遠不會被刪的話，就不用下載回來我們的網站，在html裡直接連到github 就可以了。

上面的範例是 hook 在 wp_footer，但我覺得hook 在 ‘woocommerce_after_checkout_form’ 應該會更好，或直接修改掉 form-checkout.php。

我做完的畫面：

我是直接修改 form-checkout.php 加入下面這一段：

<script type='text/javascript' src="<?php echo get_stylesheet_directory_uri(); ?>/js/jquery.twzipcode.min.js"></script>
<script>
//感謝 essoduke 大的郵遞區號專案 https://github.com/essoduke/jQuery-TWzipcode
//路徑視使用需求而改，預設是抓取目前使用的主題 /js/ 目錄下的 jquery.twzipcode.min.js 檔案
//可以從 https://raw.githubusercontent.com/essoduke/jQuery-TWzipcode/master/jquery.twzipcode.min.js 這裡抓下來放進去

jQuery(document).ready(function(){
 jQuery('<div id="billing_twzipcode"></div>').insertBefore('#billing_address_1');
 jQuery('<div id="shipping_twzipcode"></div>').insertBefore('#shipping_address_1');
 function changecb(){
 if (jQuery(this)[0].parentNode.id == 'shipping_twzipcode'){
 jQuery('#shipping_twzipcode').twzipcode('get', function (county, district, zipcode) {
 jQuery('#shipping_state').val(county);
 jQuery('#shipping_city').val(district);
 jQuery('#shipping_postcode').val(zipcode);
 });
 } else {
 jQuery('#billing_twzipcode').twzipcode('get', function (county, district, zipcode) {
 jQuery('#billing_state').val(county);
 jQuery('#billing_city').val(district);
 jQuery('#billing_postcode').val(zipcode);
 });
 }
 }
 //billing
 jQuery('#billing_twzipcode').twzipcode({
 readonly:true,
 onCountySelect:changecb,
 onDistrictSelect:changecb,
 'countySel' : jQuery('#billing_state').val(),
 'districtSel' : jQuery('#billing_city').val(),
 });
 //shipping
 jQuery('#shipping_twzipcode').twzipcode({
 readonly:true,
 onCountySelect:changecb,
 onDistrictSelect:changecb,
 'countySel' : jQuery('#shipping_state').val(),
 'districtSel' : jQuery('#shipping_city').val(),
 });
});
</script>

我用的 functions.php

add_filter('woocommerce_default_address_fields', 'cwp_custom_address_fields');
function cwp_custom_address_fields($fields) {

 $fields2['first_name'] = $fields['first_name'];
 $fields2['first_name']['class'] = array('form-row-wide');
 //$fields2['last_name'] = $fields['last_name'];
 $fields2['state'] = $fields['state'];
 //$fields2['state']['class'] = array('form-row-first');
 $fields2['state']['class'] = array('hidden');
 //$fields2['state']['label_class'] = array('hidden');
 $fields2['state']['required'] = false;
 $fields2['state']['type'] = 'text';
 
 $fields2['postcode'] = $fields['postcode'];
 //$fields2['postcode']['class'] = array('form-row-last');
 $fields2['postcode']['class'] = array('hidden');
 $fields2['postcode']['required'] = false;
 $fields2['postcode']['type'] = 'text';
 
 $fields2['city'] = $fields['city'];
 $fields2['city']['label'] = '鄉鎮[市]區';
 $fields2['city']['class'] = array('hidden');
 $fields2['city']['required'] = false;
 $fields2['city']['type'] = 'text';
 
 //$fields2['city']['class'] = array('form-row-first');
 $fields2['address_1'] = $fields['address_1'];
 $fields2['address_1']['required'] = false;

 //$fields2['address_1']['class'] = array('form-row-last');
 if (isset($fields['email'])) {
 $fields2['email'] = $fields['email'];
 }
 if (isset($fields['phone'])) {
 $fields2['phone'] = $fields['phone'];
 }
 //$fields2['country'] = $fields['country'];
 //$fields2['company'] = $fields['company'];
 //$fields2['address_2'] = $fields['address_2'];

 return $fields2;
}

說明：我還是保留了 state 來放「縣市」，保留city放「鄉鎮[市]區」，由於設定[‘class’] = array(‘hidden’); 或是設定 type=’hidden’ 都無效，所以 type保留為 ‘text’, 在 cart-shipping.php 裡增加 javascript 把整個 P 的 tag (field) 都hide 起來即可。

資料來源：