我试图从搜索表单中获取用户输入，根据用户输入构建查询，然后使用AJAX返回相关帖子。

现在，表单构建select 正确下拉列表。表单内容在提交时消失，加载动画出现，然后显示结果。我遇到的问题是返回的实际结果-无论我做什么（即使是简单的echo: \'Success\'; 不起作用），我得到0 作为我的回报。

表单代码：

<form class="form-horizontal" id="product_search_form" name="product_search_form" method="post">
  <div id="product_search_form_content">
    <div class="form-group">
        <label for="inputCarrierSelect" class="col-sm-2 control-label">Carrier</label>
        <div class="col-sm-10">
            <?php sms_populate_carrier_dropdown(); ?>
        </div>
    </div>
    <div class="form-group">
        <label for="inputStateSelect" class="col-sm-2 control-label">State</label>
        <div class="col-sm-10">
            <?php sms_populate_state_dropdown(); ?>
        </div>
        <input type="hidden" name="prdlnSelect" value="<?php echo $pl_slug; ?>" />
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <input class="btn btn-primary" id="submit_button" onclick="product_search();" type="button" value="Search" />
        </div>
    </div>
  </div>
</form>

function product_search(){
  jQuery.ajax({
    data: jQuery(\'#product_search_form\').serialize(),
    type: jQuery(\'#product_search_form\').attr(\'method\'),
    url:  the_ajax_productSearch.ajaxurl_productSearch,
    beforeSend: function(){
      jQuery(\'#product_search_form_content\').remove();
      jQuery(\'#product_search_form\').append(\'<div class="alert alert-success" role="alert" align="center"><span class="glyphicon glyphicon-refresh glyphicon-refresh-animate"></span> Loading...</div>\');
    },

    success: function(response) { // on success..
      jQuery(\'#product_search_form\').html(response);
    },
  });
  return false; // cancel original event to prevent form submitting
}

wp_register_script( \'ajax-productSearch\', get_template_directory_uri() .\'/js/ajax-product-search.js\', array( \'jquery\') );
wp_enqueue_script( \'ajax-productSearch\' );
wp_localize_script( \'ajax-productSearch\',\'the_ajax_productSearch\', array(\'ajaxurl_productSearch\' => admin_url(\'admin-ajax.php\')));

add_action( \'wp_ajax_productSearch\', \'ajax_action_productSearch\' );
add_action( \'wp_ajax_nopriv_productSearch\', \'ajax_action_productSearch\' );

function ajax_action_productSearch(){
  echo \'Success\';
  die();
}