无法正确解析JSON正文
我成功使用Newtonsoft库从Visual Studio 2019中的URL检索JSON正文。但是，我在解析我感兴趣的唯一变量时遇到了困难。
我在这里尝试遵循一些指南，这些指南似乎没有正确实施或没有完全理解（我对此很陌生）。 例如 Unexpected character encountered while parsing API response
RAW JSON：
{"deviceId":37,"longMacAddress":"5884e40000000439","shortMacAddress":259,"hoplist":"(259,3)","associationTime":"2019-06-10 22:43:54","lifeCheckInterval":5,"lastLiveCheck":"2019-06-11 07:11:37","onlineStatus":1,"txPowerValue":14,"deviceType":1,"frequencyBand":1,"lastLivecheck":"2019-06-11 07:11:36","disassociationState":0,"firmwareUpdateActivated":0,"firmwareUpdatePackagesSent":0,"firmwareUpdatePackagesUnsent":0,"firmwareUpdateInProgress":0,"deviceIdOem":"-1","deviceNameOem":"-1","deviceCompanyOem":"-1","binaryInputCount":0,"binaryOutputCount":0,"analogInputCount":0,"characterStringCount":1,"location":[{"location":"UK","locationWriteable":1,"changedAt":"2019-06-10 23:40:50"}],"description":[{"description":"DevKit","descriptionWriteable":1,"changedAt":"2019-06-10 23:40:54"}],"binaryInput":[],"binaryOutput":[],"analogInput":[],"characterString":[{"characterString":"149+0.0+99+26.5+0","characterStringWriteable":1,"changedAt":"2019-06-11 06:45:02"}]}
我的主要代码：
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
namespace API_JSON_1
{
class Program
{
static void Main(string[] args)
{
var client = new WebClient();
var JSON = client.DownloadString("http://192.168.0.254:8000/nodes/longmac/5884e40000000439");
Console.WriteLine(JSON);
Console.WriteLine("----------------------------------------------");
CharacterString CSV = JsonConvert.DeserializeObject<CharacterString>(JSON);
Console.WriteLine("Sensor data: " + CSV.CharacterStringCharacterString);
}
}
}
我的角色字符串班级：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace API_JSON_1
{
public class CharacterStrings
{
public CharacterStrings CharString { get; set; }
}
public class CharacterString
{ public string CharacterStringCharacterString { get; set; }
public long CharacterStringWriteable { get; set; }
public DateTimeOffset ChangedAt { get; set; }
}
}
输出到控制台：
{"deviceId":37,"longMacAddress":"5884e40000000439","shortMacAddress":259,"hoplis
t":"(259,3)","associationTime":"2019-06-10 22:43:54","lifeCheckInterval":5,"last
LiveCheck":"2019-06-11 06:56:37","onlineStatus":1,"txPowerValue":14,"deviceType"
:1,"frequencyBand":1,"lastLivecheck":"2019-06-11 06:56:33","disassociationState"
:0,"firmwareUpdateActivated":0,"firmwareUpdatePackagesSent":0,"firmwareUpdatePac
kagesUnsent":0,"firmwareUpdateInProgress":0,"deviceIdOem":"-1","deviceNameOem":"
-1","deviceCompanyOem":"-1","binaryInputCount":0,"binaryOutputCount":0,"analogIn
putCount":0,"characterStringCount":1,"location":[{"location":"UK","locati
onWriteable":1,"changedAt":"2019-06-10 23:40:50"}],"description":[{"description"
:"DevKit","descriptionWriteable":1,"changedAt":"2019-06-10 23:40:54"}],"binaryIn
put":[],"binaryOutput":[],"analogInput":[],"characterString":[{"characterString"
:"149+0.0+99+26.5+0","characterStringWriteable":1,"changedAt":"2019-06-11 06:45:
02"}]}
----------------------------------------------
Sensor data:
Press any key to continue . . .
很明显，我期望/希望倒数第二行显示为： “传感器数据：149 + 0.0 + 99 + 26.5 + 0”
4 个答案:
答案 0 :(得分：0)
json中的CharacterString属性是一个对象数组。这些对象中的第一个属性也是characterString。下面是一个有效的示例
输出为Sensor Data: 149+0.0+99+26.5+0
using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json;
namespace SOTest
{
class Program
{
static void Main(string[] args)
{
var json =
"{\"deviceId\":37,\"longMacAddress\":\"5884e40000000439\",\"shortMacAddress\":259,\"hoplist\":\"(259,3)\",\"associationTime\":\"2019-06-10 22:43:54\",\"lifeCheckInterval\":5,\"lastLiveCheck\":\"2019-06-11 07:11:37\",\"onlineStatus\":1,\"txPowerValue\":14,\"deviceType\":1,\"frequencyBand\":1,\"lastLivecheck\":\"2019-06-11 07:11:36\",\"disassociationState\":0,\"firmwareUpdateActivated\":0,\"firmwareUpdatePackagesSent\":0,\"firmwareUpdatePackagesUnsent\":0,\"firmwareUpdateInProgress\":0,\"deviceIdOem\":\"-1\",\"deviceNameOem\":\"-1\",\"deviceCompanyOem\":\"-1\",\"binaryInputCount\":0,\"binaryOutputCount\":0,\"analogInputCount\":0,\"characterStringCount\":1,\"location\":[{\"location\":\"UK\",\"locationWriteable\":1,\"changedAt\":\"2019-06-10 23:40:50\"}],\"description\":[{\"description\":\"DevKit\",\"descriptionWriteable\":1,\"changedAt\":\"2019-06-10 23:40:54\"}],\"binaryInput\":[],\"binaryOutput\":[],\"analogInput\":[],\"characterString\":[{\"characterString\":\"149+0.0+99+26.5+0\",\"characterStringWriteable\":1,\"changedAt\":\"2019-06-11 06:45:02\"}]}";
var obj = JsonConvert.DeserializeObject<CharacterStrings>(json);
Console.WriteLine($"Sensor Data: {obj.CharacterString.First().CharacterString}");
Console.ReadKey();
}
public class CharacterStrings
{
public List<Characters> CharacterString { get; set; }
}
public class Characters
{ public string CharacterString { get; set; }
public long CharacterStringWriteable { get; set; }
public DateTime ChangedAt { get; set; }
}
}
}
答案 1 :(得分：0)
您正在使用CharacterSting定义CSV对象。我应该是CharacterStrings，而在CharacterStrings类中，它应该是数组，因为您的JSON是数组
答案 2 :(得分：0)
欢迎使用StackOverflow！
将json字符串转换为对象时（例如：反序列化），您需要记住的一点是，要将字符串转换为的对象需要与json字符串的格式匹配。就您而言，json字符串与您要转换的对象不匹配。
一旦有了正确的对象，这将为您提供所需的输出：
@CrossOrigin("*")
@PostMapping("/login")
public userLogin(@RequestedBody modalName objectname){
//Service Call
}
编辑以解释上面的代码：由于 static void Main(string[] args)
{
string JSON = "{\"deviceId\":37,\"longMacAddress\":\"5884e40000000439\",\"shortMacAddress\":259,\"hoplist\":\"(259,3)\",\"associationTime\":\"2019-06-10 22:43:54\",\"lifeCheckInterval\":5,\"lastLiveCheck\":\"2019-06-11 07:11:37\",\"onlineStatus\":1,\"txPowerValue\":14,\"deviceType\":1,\"frequencyBand\":1,\"lastLivecheck\":\"2019-06-11 07:11:36\",\"disassociationState\":0,\"firmwareUpdateActivated\":0,\"firmwareUpdatePackagesSent\":0,\"firmwareUpdatePackagesUnsent\":0,\"firmwareUpdateInProgress\":0,\"deviceIdOem\":\"-1\",\"deviceNameOem\":\"-1\",\"deviceCompanyOem\":\"-1\",\"binaryInputCount\":0,\"binaryOutputCount\":0,\"analogInputCount\":0,\"characterStringCount\":1,\"location\":[{\"location\":\"UK\",\"locationWriteable\":1,\"changedAt\":\"2019-06-10 23:40:50\"}],\"description\":[{\"description\":\"DevKit\",\"descriptionWriteable\":1,\"changedAt\":\"2019-06-10 23:40:54\"}],\"binaryInput\":[],\"binaryOutput\":[],\"analogInput\":[],\"characterString\":[{\"characterString\":\"149+0.0+99+26.5+0\",\"characterStringWriteable\":1,\"changedAt\":\"2019-06-11 06:45:02\"}]}";
Console.WriteLine(JSON);
Console.WriteLine("----------------------------------------------");
RootObject CSV = JsonConvert.DeserializeObject<RootObject>(JSON);
// Option 1: Loop over the items in your List<CharacterString>...
foreach (var cs in CSV.characterString)
{
Console.WriteLine("Sensor data: " + cs.characterString);
}
// Option 2: Or, if you know there is only one in the list...
Console.WriteLine("Sensor data: " + CSV.characterString.First().characterString);
}
是characterString，因此从技术上讲，该列表中可能有多个项目。选项1：如果需要，您可以遍历该列表以显示其中的项目。但是，如果可以肯定地知道列表中只有一项，那么方法2：您只需在列表中显示.First（）项即可。
我拿了您给我们的json字符串，然后使用这个方便的网站（http://json2csharp.com/#）将其转换为以下类：
List<CharacterString>答案 3 :(得分：0)
要使其正常工作，您必须像这样修改类：
public class CharacterStrings
{
public List<CharacterStringObject> CharacterString { get; set; }
}
public class CharacterStringObject
{
public string CharacterString { get; set; }
public long CharacterStringWriteable { get; set; }
public DateTime ChangedAt { get; set; }
}
之后，在您像这样读取JSON之后：
CharacterString CSV = JsonConvert.DeserializeObject<CharacterString>(JSON);
最后得到List<CharacterStringObject>，其中包含一个元素。因此，您可以像这样打印第一个：
Console.WriteLine("Sensor data: " + CSV.CharacterString.First().CharacterString);
干杯，
编辑：使用给定的JSON在本地进行测试，效果很好
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