ASP.NET Core API 中的 FromBody 返回 null

Question

我在 Azure Service Fabric 中创建了一个有状态的 ASP.NET Core 服务，其中包含 10 个分区，API 作为项目模板和 ASP.NET Core 3.0。我正在尝试通过 JSON 中的 Postman 将类 SupplierMaterialMaintenance 的对象发送到我的有状态服务，如下图所示：-

这是我要发送的 JSON 文件。

{
    "SupplierMaterialAssociationGuid": "6ef61a2b-963e-4993-ac73-5e07f707c2e2",
    "MinimumOrderQuantity": 1,
    "UnitOfMeasurementGuid": "771d4f76-9321-442f-b2c2-9f75b1a7cda8",
    "ConversionFactor": 2,
    "POPrice": 123.00000,
    "OrderLeadTime": 10,
    "IssueMinimumLot": 0,
    "ContainerQuantity": 10,
    "InnerContainerQuantity": 1,
    "NoOfInnerContainers": 10,
    "SupplierMaterialNumber": null,
    "SupplierMaterialName": null,
    "POPriceExcludingMetal": 123.00000,
    "InitialVolumeQuantity": 1,
    "ReplacementMaterialNumber": "",
    "MetalWeight": 0.0,
    "MetalRate": 0.0,
    "StandardBoxLength": 0.0,
    "StandardBoxHeight": 0.0,
    "StandardBoxWidth": 0.0,
    "StandardPackFactor": 10,
    "FullBoxWeight": 0.0,
    "TariffCodeGuid": "00000000-0000-0000-0000-000000000000",
    "CountryRegionsAssociationGuid": "00000000-0000-0000-0000-000000000000",
    "ExpiryDate": "0001-01-01T00:00:00",
    "IsActive": true,
    "MatSuppMainSupplier": false,
    "EUPreferentialOriginStatusCode": null,
    "Id": "ead6cbc7-baff-430d-b83b-4914a916aabd",
    "Name": null,
    "CreatedDate": "2019-07-09T01:53:49.659194",
    "ModifiedDate": "2019-07-09T01:53:49.659194",
    "CreatedBy": "13beef85-3939-4998-b912-22d8df2cd966",
    "ModifiedBy": "13beef85-3939-4998-b912-22d8df2cd966",
    "IsRowChecked": false,
    "Version": null,
    "CrudOperationType": 0,
    "Error": null
}

这是我的控制器：-

using Microsoft.AspNetCore.Mvc;
using Microsoft.ServiceFabric.Data;
using Microsoft.ServiceFabric.Data.Collections;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MyStatefulService.Models;
using System.Net.Http;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json;

namespace MyStatefulService.Controllers
{
    [Produces("application/json")]
    [Route("api/[controller]")]
    [ApiController]
    public class DefaultController : Controller
    {
        private readonly IReliableStateManager reliableStateManager;

        public DefaultController(IReliableStateManager reliableStateManager)
        {
            this.reliableStateManager = reliableStateManager;
        }

        // GET api/Default
        [HttpGet]
        public async Task<IActionResult> Get()
        {
            CancellationToken ct = new CancellationToken();

            IReliableDictionary<Guid, SupplierMaterialMaintenance> myDictionary = await this.reliableStateManager.GetOrAddAsync<IReliableDictionary<Guid, SupplierMaterialMaintenance>>("dictionary");

            using (ITransaction tx = this.reliableStateManager.CreateTransaction())
            {
                Microsoft.ServiceFabric.Data.IAsyncEnumerable<KeyValuePair<Guid, SupplierMaterialMaintenance>> list = await myDictionary.CreateEnumerableAsync(tx);

                Microsoft.ServiceFabric.Data.IAsyncEnumerator<KeyValuePair<Guid, SupplierMaterialMaintenance>> enumerator = list.GetAsyncEnumerator();

                List<KeyValuePair<Guid, SupplierMaterialMaintenance>> result = new List<KeyValuePair<Guid, SupplierMaterialMaintenance>>();

                while (await enumerator.MoveNextAsync(ct))
                {
                    result.Add(enumerator.Current);
                }

                return this.Json(result);
            }
        }

        // PUT api/Default/name
        [HttpPost]
        public async Task<IActionResult> Post([FromBody] SupplierMaterialMaintenance obj)
        {
            SupplierMaterialMaintenance obj1 = new SupplierMaterialMaintenance();
            if (ModelState.IsValid)
            {
                obj1 = obj;
            }
            IReliableDictionary<Guid, SupplierMaterialMaintenance> myDictionary = await this.reliableStateManager.GetOrAddAsync<IReliableDictionary<Guid, SupplierMaterialMaintenance>>("dictionary");

            using (ITransaction tx = this.reliableStateManager.CreateTransaction())
            {
                await myDictionary.AddOrUpdateAsync(tx, obj1.SupplierMaterialAssociationGuid, obj1, (key, oldvalue) => obj1);
                await tx.CommitAsync();
            }

            return new OkResult();
        }
    }
}

这里是 SupplierMaterialMaintenance 类：-

public class SupplierMaterialMaintenance : IComparable<SupplierMaterialMaintenance>, IEquatable<SupplierMaterialMaintenance>
    {

        public Guid SupplierMaterialAssociationGuid;
        public int MinimumOrderQuantity;
        public Guid UnitOfMeasurementGuid;
        public int ConversionFactor;
        public decimal POPrice;
        public int OrderLeadTime;
        public int IssueMinimumLot;
        public int ContainerQuantity;
        public int InnerContainerQuantity;
        public int NoOfInnerContainers;
        public string SupplierMaterialNumber;
        public string SupplierMaterialName;
        public decimal POPriceExcludingMetal;
        public int InitialVolumeQuantity;
        public string ReplacementMaterialNumber;
        public decimal MetalWeight;
        public decimal MetalRate;
        public decimal StandardBoxLength;
        public decimal StandardBoxHeight;
        public decimal StandardBoxWidth;
        public int StandardPackFactor;
        public decimal FullBoxWeight;
        public Guid TariffCodeGuid;
        public Guid CountryRegionsAssociationGuid;
        public DateTime ExpiryDate;
        public bool IsActive;
        public bool MatSuppMainSupplier;
        public string EUPreferentialOriginStatusCode;
        public Guid Id;
        public string Name;
        public string CreatedDate;
        public string ModifiedDate;
        public Guid CreatedBy;
        public Guid ModifiedBy;
        public bool IsRowChecked;
        public string Version;
        public int CrudOperationType;
        public string Error;

        public int CompareTo(SupplierMaterialMaintenance obj)
        {
            if (obj != null)
            {
                SupplierMaterialMaintenance otherObj = obj as SupplierMaterialMaintenance;

                if (otherObj != null)
                {
                    return otherObj.SupplierMaterialAssociationGuid.CompareTo(this.SupplierMaterialAssociationGuid);
                }
                else
                {
                    throw new ArgumentException("Object is not a SupplierMaterialMaintenance");
                }
            }
            return 1;
        }

        public bool Equals(SupplierMaterialMaintenance obj)
        {
            if (obj == null) return false;

            return obj.SupplierMaterialAssociationGuid.Equals(this.SupplierMaterialAssociationGuid);
        }
    }

每当我点击 Postman 中的发送按钮时，我总是会得到一个使用默认值初始化的 X 类对象，如下所示：-

我在 StackOverflow 上搜索了许多问题，但没有成功。我在这里做错了什么？

Answer 1

您需要使用getter 和setter 将SupplierMaterialMaintenance 类中的所有fields 更改为properties

public class SupplierMaterialMaintenance : IComparable<SupplierMaterialMaintenance>, IEquatable<SupplierMaterialMaintenance>
{
    public Guid SupplierMaterialAssociationGuid { get; set; }
    public int MinimumOrderQuantity { get; set; }
    public Guid UnitOfMeasurementGuid { get; set; }
    public int ConversionFactor { get; set; }
    //goes like this...

你可以看看Microsoft Documentation.net-core中的Model Binding

Answer 2

既然是ASP.NET Core 3.0：你还在用NewtonSoft,Json，还是切换到System.Text.Json？

默认情况下，ASP.NET Core 在 Json 端使用 camelCase 与 Json 进行序列化。因此，您尝试发布的数据应该类似于

{

    "supplierMaterialAssociationGuid": "6ef61a2b-963e-4993-ac73-5e07f707c2e2",
    "minimumOrderQuantity": 1,
    "unitOfMeasurementGuid": "771d4f76-9321-442f-b2c2-9f75b1a7cda8",
    "conversionFactor": 2,

    ...

}

取自这个 NewtonSoft.Json Serialization Guide，如果您正在使用 NewtonSoft.Json并且手动（反）序列化，则使用字段应该可以正常工作。对于模型绑定，您需要使用answer from darcane 中解释的属性。

默认情况下，类型的属性以退出模式序列化。这意味着所有带有 getter 的公共字段和属性都会自动序列化为 JSON，而不应序列化的字段和属性会通过在其上放置 JsonIgnoreAttribute 来选择退出。