微信小程序提交 webapi FormDataCollection

/// <returns></returns>
        [HttpPost]
        public ShoppingCartModel UpdateCart(FormDataCollection form)
        {}

var data =new Array();  

    var items = this.data.items;
    items.forEach(v => { 
      if (v.selected) { 
        var key = "itemquantity" + v.id;
        var value = v.inputQuantity 
        data.push({key,value});
      }
    });