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首页 > 解决方案 > 无法反序列化当前的 JSON 数组（例如 [1,2,3]）& {“解析值时遇到意外字符：e. Path '', line 0, position 0.”}

c# - 无法反序列化当前的 JSON 数组（例如 [1,2,3]）& {“解析值时遇到意外字符：e. Path '', line 0, position 0.”}

问题描述

我看到很多类似的问题，但这次我真的无法解决。我遇到的问题是用某个对象的内容填充视图以更新它。当我按下“编辑”时，理论上，所有字段都应该自动插入。到目前为止我尝试了什么？

        public ActionResult CreateOrEdit(int id = 0)
    {
        if (id==0)
            return View(new Recipe());
        else
        {
            HttpResponseMessage response = GlobalVariables.client.GetAsync(id.ToString()).Result;
            //return ViewJsonConvert.DeserializeObject<IList<Recipe>>(response.ToString()));
            return View(response.Content.ReadAsAsync<Recipe>().Result);
            //return View(new Recipe());
        }
    }

return View(response.Content.ReadAsAsync<Recipe>().Result);- 当使用它作为回报时，我收到这个错误：

无法反序列化当前的 JSON 数组（例如 [1,2,3]）

查找问题后，我尝试了以下操作： return View(JsonConvert.DeserializeObject<IList<Recipe>>(response.ToString()));这让我遇到了这个错误：

{"解析值时遇到意外字符：s.Path '', line 0, position 0."}

在这一点上，我被卡住了。我假设它正在尝试反序列化以下 JSON：

 {
    "id": 5002,
    "name": "Test Recipe",
    "recipeLink": "testlink",
    "category1Id": 7757,
    "category2Id": 7758,
    "category3Id": 7759,
    "category4Id": 7760,
    "recipeById": 1,
    "totalTime": 30,
    "totalTimeUnitId": 1,
    "activeTime": 20,
    "activeTimeUnitId": 1,
    "instructions": "Test Instructions",
    "sourceKey": "Test SK",
    "recipeBy": "TestPerson",
    "insertedAtUtc": "2019-09-04T12:18:48.0466667",
    "isVerified": 1,
    "numPersons": 5
}

如果需要，这里是处理操作的 API 控制器的代码。

 [Route("v1/recipe/{id}")]
    [HttpPut()]
    public IActionResult UpdateList(int id, [FromBody]Recipe recipe)
    {
        var category1Id = 7757;
        var category2Id = 7758;
        var category3Id = 7759;
        var category4Id = 7760;
        var isVerified = 0;
        var recipeBy = "TestPerson";
        var recipeById = 1;

        try
        {
            if (recipe == null) throw new ArgumentException("No data specified");
            //if (newData.Name == null) throw new ArgumentException("No name specified");

            using (var con = _connFactory())
            {
                con.Execute(@"UPDATE dbo.Recipe SET Name=@name, RecipeLink=@recipeLink, Category1Id=@category1Id ,Category2Id=@category2Id, 
                            Category3Id=@category3Id, Category4Id=@category4Id, RecipeById=@recipeById, TotalTime=@totalTime, TotalTimeUnitId=@totalTimeUnitId, 
                            ActiveTime=@activeTime, ActiveTimeUnitId=@activeTimeUnitId, Instructions=@instructions, SourceKey=@sourceKey, RecipeBy=@recipeBy, 
                            InsertedAtUtc=getutcdate(), IsVerified=@isVerified, NumPersons=@numPersons  WHERE Id=@id",
                            new
                            {
                                id,
                                recipe.name,
                                recipe.recipeLink,
                                category1Id,
                                category2Id,
                                category3Id,
                                category4Id,
                                recipeById,
                                recipe.totalTime,
                                recipe.totalTimeUnitId,
                                recipe.activeTime,
                                recipe.activeTimeUnitId,
                                recipe.instructions,
                                recipe.sourceKey,
                                recipeBy,
                                isVerified,
                                recipe.numPersons
                            });
            }
            return Ok(recipe);
        }
        catch (Exception exc)
        {
            return BadRequest();
        }
    }

标签： c#asp.netjsonsql-server

解决方案

我相信您的response字符串以 Unicode 字节顺序标记字符开头。

例如...

using Newtonsoft.Json;

namespace StackOverflow
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            var json = @"{
    'id': 5002,
    'name': 'Test Recipe',
    'recipeLink': 'testlink',
    'category1Id': 7757,
    'category2Id': 7758,
    'category3Id': 7759,
    'category4Id': 7760,
    'recipeById': 1,
    'totalTime': 30,
    'totalTimeUnitId': 1,
    'activeTime': 20,
    'activeTimeUnitId': 1,
    'instructions': 'Test Instructions',
    'sourceKey': 'Test SK',
    'recipeBy': 'TestPerson',
    'insertedAtUtc': '2019-09-04T12:18:48.0466667',
    'isVerified': 1,
    'numPersons': 5
}".Replace("'", "\"");

            //This works...
            var deserialized1 = JsonConvert.DeserializeObject(json);

            //Prepend a U+FEFF Byte Order Mark character...
            json = "\uFEFF" + json;

            //This fails with error:
            //Newtonsoft.Json.JsonReaderException:
            //Unexpected character encountered while parsing value: . Path '', line 0, position 0.
            var deserialized2 = JsonConvert.DeserializeObject(json);
        }
    }
}

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