// 构造请求 UnityWebRequest request = new UnityWebRequest(url, "POST"); byte[] bodyRaw = System.Text.Encoding.UTF8.GetBytes(json); request.uploadHandler = (UploadHandler)new UploadHandlerRaw(bodyRaw); request.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer(); request.SetRequestHeader("Content-Type", "application/json"); // 发送请求 yield return request.SendWebRequest(); // 处理返回结果 if (request.isNetworkError) { Debug.Log(request.error); resultText.text = request.error; }替换掉result,unity版本太老，总是报错

如果您的 Unity 版本太老，无法使用 Result 枚举类型，您可以使用以下方式替换代码中的 `request.isNetworkError`：

// 构造请求
UnityWebRequest request = new UnityWebRequest(url, "POST");
byte[] bodyRaw = System.Text.Encoding.UTF8.GetBytes(json);
request.uploadHandler = (UploadHandler)new UploadHandlerRaw(bodyRaw);
request.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer();
request.SetRequestHeader("Content-Type", "application/json");

// 发送请求
yield return request.Send();

// 处理返回结果
if (request.isError)
{
    Debug.Log(request.error);
    resultText.text = request.error;
}

这段代码中使用了 `request.isError` 来判断是否发生网络错误。如果 `isError` 为 true，则表示发生了网络错误，可以通过 `request.error` 获取错误信息。

相关问题

using UnityEngine; using UnityEngine.Networking; using System.Collections; using System.Collections.Generic; using LitJson; public class Example : MonoBehaviour { public UnityEngine.UI.Text resultText; void Start() { StartCoroutine(PostRequest()); } IEnumerator PostRequest() { string url = "your_post_url_here"; string postData = "your_post_data_here"; // Send POST request UnityWebRequest request = new UnityWebRequest(url, "POST"); byte[] bodyRaw = System.Text.Encoding.UTF8.GetBytes(postData); request.uploadHandler = new UploadHandlerRaw(bodyRaw); request.downloadHandler = new DownloadHandlerBuffer(); request.SetRequestHeader("Content-Type", "application/json"); yield return request.SendWebRequest(); // Parse response if (request.result == UnityWebRequest.Result.Success) { string json = request.downloadHandler.text; JsonData data = JsonMapper.ToObject(json); string result = "Return Code: " + data["returnCode"] + "\n"; result += "Return Message: " + data["returnMessage"] + "\n"; result += "Data: " + data["data"] + "\n"; resultText.text = result; } else { Debug.Log(request.error); } } }修改代码

根据你提供的代码，可能会有以下几个问题：

1. 在 `UnityWebRequest` 类的构造函数中，第一个参数应该是请求的 URL 地址，而不是字符串 `"POST"`。你需要将 `url` 变量作为第一个参数传递给构造函数。

2. 在 `UnityWebRequest` 类的构造函数中，第二个参数应该是请求的 HTTP 方法，即 `"POST"` 或 `"GET"` 等。由于你的请求是 POST 请求，因此你需要将字符串 `"POST"` 作为第二个参数传递给构造函数。

3. 在发送请求之前，你需要设置请求的超时时间。可以使用 `request.timeout` 属性来设置超时时间，单位为秒。

4. 在请求头中，你设置了 `Content-Type` 为 `"application/json"`。如果你的请求数据不是 JSON 格式，那么你需要将 `Content-Type` 设置为相应的类型，例如 `"application/x-www-form-urlencoded"`。

下面是修改后的代码：

using UnityEngine;
using UnityEngine.Networking;
using System.Collections;
using System.Collections.Generic;
using LitJson;

public class Example : MonoBehaviour
{
    public UnityEngine.UI.Text resultText;

    void Start()
    {
        StartCoroutine(PostRequest());
    }

    IEnumerator PostRequest()
    {
        string url = "your_post_url_here";
        string postData = "your_post_data_here";

        // Send POST request
        UnityWebRequest request = new UnityWebRequest(url, "POST");
        byte[] bodyRaw = System.Text.Encoding.UTF8.GetBytes(postData);
        request.uploadHandler = new UploadHandlerRaw(bodyRaw);
        request.downloadHandler = new DownloadHandlerBuffer();
        request.SetRequestHeader("Content-Type", "application/json");
        request.timeout = 10;  // Set request timeout to 10 seconds
        yield return request.SendWebRequest();

        // Parse response
        if (request.result == UnityWebRequest.Result.Success)
        {
            string json = request.downloadHandler.text;
            JsonData data = JsonMapper.ToObject(json);
            string result = "Return Code: " + data["returnCode"] + "\n";
            result += "Return Message: " + data["returnMessage"] + "\n";
            result += "Data: " + data["data"] + "\n";
            resultText.text = result;
        }
        else
        {
            Debug.Log(request.error);
        }
    }
}

using System.Collections; using UnityEngine; using UnityEngine.Networking; using UnityEngine.UI; using Newtonsoft.Json.Linq; using System.Collections.Generic; using System; public class KN_Data : MonoBehaviour { // Start is called before the first frame update public Dropdown dropdown; IEnumerator Start() { // 定义接口地址 string url = "http://158.58.50.21:8886/baseinfo/queryBaseInfo"; // 构造请求参数 var requestData = new { countryid = 3, areaid = 22, lineid = 27, metroid = 279, carriageid = "" }; string json = JsonMapper.ToJson(requestData); // 构造请求 UnityWebRequest request = new UnityWebRequest(url, "POST"); byte[] bodyRaw = System.Text.Encoding.UTF8.GetBytes(json); request.uploadHandler = (UploadHandler)new UploadHandlerRaw(bodyRaw); request.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer(); request.SetRequestHeader("Content-Type", "application/json"); // 发送请求 yield return request.SendWebRequest(); // 处理返回结果 if (request.isNetworkError) { Debug.Log(request.error); resultText.text = request.error; } else { string json = www.downloadHandler.text; // 解析json数据，获取下拉选项框的内容 List<string> options = new List<string>(); JObject jo = JObject.Parse(json); JArray ja = (JArray)jo["data"]; for(int i = 0; i < ja.Count; i++) { JObject item = (JObject)ja[i]; options.Add(item["carriagename"].ToString()); } // 将内容设置到下拉选项框中 Dropdown dropdown = GetComponent<Dropdown>(); dropdown.ClearOptions(); dropdown.AddOptions(options); } } }修改代码中的错误

在代码中，需要将以下这行代码：

string json = www.downloadHandler.text;

修改为：

string json = request.downloadHandler.text;

因为在代码中已经使用了 `UnityWebRequest` 对象 `request` 处理请求和返回结果，而非使用 `www` 对象。