Question

我在从this API仅获取价格值时遇到了麻烦。我不需要来自Web URL的所有JSON，我只需要"rate":"3,394.2033"部分。

API数据：

{
  "time": {
    "updated": "Feb 6, 2019 22:02:00 UTC",
    "updatedISO": "2019-02-06T16:02:00-06:00",
    "updateduk": "Feb 6, 2019 at 22:02 GMT"
  },
  "disclaimer": "This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org",
  "bpi": {
    "USD": {
      "code": "USD",
      "rate": "3,394.2033",
      "description": "United States Dollar",
      "rate_float": 3394.2033
    },
    "XBT": {
      "code": "XBT",
      "rate": "1.0000",
      "description": "Bitcoin",
      "rate_float": 1
    }
  }
}

我的代码：

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class API : MonoBehaviour
{
    private string www = 
    "https://api.coindesk.com/v1/bpi/currentprice/XBT.json";
    public Text responseText;

    public void Request()
    {
        WWW request = new WWW(www);
        StartCoroutine(OnResponse(request));
    }
    private IEnumerator OnResponse(WWW req)
    {
        yield return req;

        responseText.text = req.text;
    }
}

该脚本允许我提取所有JSON数据，但我只需要"rate":"3,394.2033"。更具体地说，就是值3,394.2033。

Answer 1

使用Json.Net的LINQ-to-JSON API（JTokens），您可以用一行代码来做到这一点：

2019-02-07 10:23:01 DEBUG BasicClientConnectionManager:158 - Get connection for route {}->http://demo0667044.mockable.io
2019-02-07 10:23:01 DEBUG DefaultClientConnectionOperator:174 - Connecting to demo0667044.mockable.io:80
2019-02-07 10:23:02 DEBUG DefaultClientConnection:176 - Connection org.apache.http.impl.conn.DefaultClientConnection@23ceabc1 closed
2019-02-07 10:23:02 DEBUG DefaultClientConnection:160 - Connection org.apache.http.impl.conn.DefaultClientConnection@23ceabc1 shut down
2019-02-07 10:23:02 DEBUG BasicClientConnectionManager:196 - Releasing connection org.apache.http.impl.conn.ManagedClientConnectionImpl@5d5eef3d
java.net.ConnectException: Connection refused: connectOutput : 
 null

    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:117)
    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:177)
    at org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:304)
    at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:611)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:446)
    at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:863)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57)
    at com.util.TestJavaFile.testMockWS(TestJavaFile.java:128)
    at com.util.TestJavaFile.main(TestJavaFile.java:57)

提琴：https://dotnetfiddle.net/Krgejr

Answer 2

您可以使用newtonsoft并在此处遵循以下示例：https://www.newtonsoft.com/json/help/html/SerializingJSONFragments.htm

public class SearchResult
{
    public string Rate { get; set; }
}


JObject rateSearch = JObject.Parse(MyJsonText);

// get JSON result objects into a list
IList<JToken> results = rateSearch ["bpi"]["USD"].Children().ToList();

// serialize JSON results into .NET objects
IList<SearchResult> searchResults = new List<SearchResult>();
foreach (JToken result in results)
{
    // JToken.ToObject is a helper method that uses JsonSerializer internally
    SearchResult searchResult = result.ToObject<SearchResult>();
    searchResults.Add(searchResult);
}

Answer 3

您还可以使用Unity社区中的旧金SimpleJSON

要在Unity中使用SimpleJSON，只需将SimpleJSON.cs文件复制到资产文件夹内的项目“ plugins”文件夹中。

然后做

point = Point([10, 14, 15, 10, 5])
print(point.weights)

调试说明

如果未找到与给定的键相反的键，则会返回var json = JSON.Parse(req.text); var yourText = json["bpi"]["USD"]["rate"];而不是引发异常。

Answer 4

您可以使用 UnityWebRequest.Get 获取 JSON，然后使用库对其进行反序列化（我推荐 NewtonSoft.Json）。

反序列化 JSON 后，您可以从结果对象中选择要使用的属性。

我整理了一个教程来做这件事，还有更多。

https://www.youtube.com/watch?v=Yp8uPxEn6Vg

从API获取Json数据并在Unity C＃中仅显示json的一部分

4 个答案: