我有一个问题，从Woocommerce $item对象获取一些值。
我试图从“ meta数据”-〉“_advanced_woo_discount_item_total_discount”-〉初始价格，折扣价格和“折扣值”中提取数据。
我用$item->get_meta_data();试过了，但是得到了一个空白的返回。

{
    "id":55,
    "order_id":11501,
    "name":"test",
    "product_id":6419,
    "variation_id":6421,
    "quantity":1,
    "tax_class":"",
    "subtotal":"182.491803",
    "subtotal_tax":"40.15",
    "total":"182.491803",
    "total_tax":"40.15",
    "taxes":{
      "total":{"1":"40.148197"},
      "subtotal":{"1":"40.148197"}
    },
    "meta_data":[{
        "id":457,
        "key":"pa_velikost",
        "value":"180cm"
      },
      {
        "id":458,
        "key":"_advanced_woo_discount_item_total_discount",
        "value":
        {
          "initial_price":278.3,
          "discounted_price":222.64000000000001,
          "total_discount_details":
          {
            "8e39099d383d7d50a8c4fce98e59cc79":
            {
              "1":
              {
                "set_discount":0,
                "bulk_discount":0,
                "simple_discount":
                {
                  "discount_type":"percentage",
                  "discount_value":"20",
                  "discount_quantity":1,
                  "discount_price_per_quantity":55.660000000000004,
                  "discount_price":55.660000000000004
                }
              }
            }
          },
          "cart_discount_details":[],
          "apply_as_cart_rule":["no"],
          "discount_lines":
          {
            "non_applied":{
              "quantity":0,
              "discount":0,
              "price":278.3,
              "calculate_discount_from":278.3
            },
            "0":
            {
              "quantity":1,
              "discount":55.660000000000004,
              "original_price":278.3,
              "discounted_price":222.64000000000001
            }
          },
          "cart_quantity":1,
          "product_id":6421,
          "initial_price_based_on_tax_settings":278.3,
          "discounted_price_based_on_tax_settings":222.64000000000001
        }
      }
        ]
      }