虽然你确实可以在谷歌上搜索，但这可能就是你首先来到这里的原因。上面提到的插件都是可供选择的，但如果您仍然想这样做，下面是如何将城市字段变成下拉列表：

/**
 * Change the checkout city field to a dropdown field.
 */
function jeroen_sormani_change_city_to_dropdown( $fields ) {

    $city_args = wp_parse_args( array(
        \'type\' => \'select\',
        \'options\' => array(
            \'city1\' => \'name city 1\',
            \'city2\' => \'name city 2\',
            \'city3\' => \'name city 3\',
        ),
    ), $fields[\'shipping\'][\'shipping_city\'] );

    $fields[\'shipping\'][\'shipping_city\'] = $city_args;
    $fields[\'billing\'][\'billing_city\'] = $city_args; // Also change for billing field

    return $fields;

}
add_filter( \'woocommerce_checkout_fields\', \'jeroen_sormani_change_city_to_dropdown\' );