ASP.NET Core Web API中JSON反序列化对象错误排查求助

错误信息 #

{"errors": {"Listmodel": ["Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[sistap_api.Models.AmbarHareketRequestModel]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path 'Listmodel', line 1, position 13."]}, "status": 400, "title": "One or more validation errors occurred.", "traceId": "00-3cd8a186e7bcd84f93c8c18bef8ca908-f4fbb2109d75914d-00", "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1"}

前端React Native请求代码 #

const ambarHareketOnay = async () => {        
        const convertedData = route.params.data.map(item => ({
            KullaniciId: parseInt(route.params.userId), 
            RuloSiparisDetayId: parseInt(item.RuloSiparisDetayID), 
            EskiLokasyonAmbar: parseInt(item.AmbarID),  
            EskiLokasyonKoridor: parseInt(item.AmbarID),  
            YeniLokasyonAmbar: parseInt(route.params.ambarId),  
            YeniLokasyonKoridor: parseInt(secilenKoridorId),  
        }));
        console.log("data: ",convertedData);
       try {

           fetch(global.apiDomain + 'api/ambarHareket', {
            method: 'post',
            headers: {
                Accept: 'application/json',
                'Content-type': 'application/json',
            },
            body: JSON.stringify({ Listmodel: convertedData }),
        })

前端转换后的数据 #

data:  [{"EskiLokasyonAmbar": 1, "EskiLokasyonKoridor": 1, "KullaniciId": 1, "RuloSiparisDetayId": 50328, "YeniLokasyonAmbar": 1, "YeniLokasyonKoridor": 1048}, {"EskiLokasyonAmbar": 1, "EskiLokasyonKoridor": 1, "KullaniciId": 1, "RuloSiparisDetayId": 50330, "YeniLokasyonAmbar": 1, "YeniLokasyonKoridor": 1048}]

后端ASP.NET Core Web API代码 #

接口控制器 #

[HttpPost]
public IActionResult ambarHareketOnay ([FromBody] List<AmbarHareketRequestModel> Listmodel)

请求模型 #

public class AmbarHareketRequestModel
{
     public int KullaniciId { get; set; }
     public int RuloSiparisDetayId { get; set; }
     public int EskiLokasyonAmbar { get; set; }
     public int EskiLokasyonKoridor { get; set; }
     public int YeniLokasyonAmbar { get; set; }
     public int YeniLokasyonKoridor { get; set; }
}

错误原因 #

后端接口期望接收的是JSON数组（对应List<AmbarHareketRequestModel>类型），但前端发送的是一个包含Listmodel字段的JSON对象，数据结构不匹配，导致反序列化失败。

解决方案 #

方案一：修改前端请求，直接发送数组 #

将请求body改为直接序列化convertedData数组，无需包装在Listmodel对象中：

body: JSON.stringify(convertedData),

方案二：修改后端接收模型，使用包装类 #

如果需要保留前端现有请求结构，可以创建一个包装类来接收数据：

public class AmbarHareketRequestWrapper
{
    public List<AmbarHareketRequestModel> Listmodel { get; set; }
}

然后更新接口参数：

[HttpPost]
public IActionResult ambarHareketOnay ([FromBody] AmbarHareketRequestWrapper request)

后续在接口逻辑中通过request.Listmodel获取数据即可。

内容的提问来源于stack exchange，提问作者İbrahim Ethem Bildirici