Unity3D WWW错误C＃

Question

I am working in Unity trying to figure out the WWW class and access API from online-go.com

I get an error in the Debug.Log though. Additionally, the Debug on Line 58 just returns a blank string. I don't think I am fully understanding how to use WWW since this is the first time I am using it.

Necessary data rewind wasn't possible UnityEngine.Debug:Log(Object) <LoadWWW>c__Iterator0:MoveNext() (at Assets/OGS.cs:60)

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System;
using System.IO;
using System.Net;
using System.Text;
//using System.Net.httpclient;

public class OGS : MonoBehaviour {

    string generateAPIClient = "http://beta.online-go.com/developer";
    string APIKey = "0c63a59dd17ec69a48af5d9dc8b4e956";
    string requestUserToken = "oauth2/access_token";
    string clientID = "";
    string clientSecret = "";
    string baseURL = "http://online-go.com/";
    string url = "";
    string username;
    string password;
    string POST;

    List<Settings> settings;
    // Use this for initialization
    void Start () {
        Debug.Log("Opened");
        settings = new List<Settings>();
        Load("Settings");
        clientID = AssignSetting("clientID");
        clientSecret = AssignSetting("clientSecret");
        username = AssignSetting("username");
        password = AssignSetting("password");
        POST = string.Format(   "client_id={0}&client_secret={1}&grant_type=password&username={2}&password={3}",
                                clientID,  clientSecret, username, password);
        url = baseURL + requestUserToken;
        StartCoroutine("LoadWWW");

    }

    //Assign settings loaded to settings variables
    string AssignSetting (string item) {
        int position = -1;
        for(int i=0;i<settings.Count;i++) {
            if(settings[i].name == item){return settings[i].value;}
        }

        return string.Empty;
    }

    IEnumerator LoadWWW() {
        byte[] byteArray = GetBytes(POST);
        Dictionary<string,string> headers = new Dictionary<string,string>();
        headers.Add("Content-Type", "application/x-www-form-urlencoded");
        WWW text = new WWW(url, byteArray, headers);
        yield return text;
        byteArray = text.bytes;
        string POSTResponse = GetString(byteArray);
        Debug.Log(POSTResponse);
        Debug.Log(text.responseHeaders);
        Debug.Log(text.error);
    }

    static byte[] GetBytes(string str)
    {
        byte[] bytes = new byte[str.Length * sizeof(char)];
        System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
        return bytes;
    }

    static string GetString(byte[] bytes)
    {
        char[] chars = new char[bytes.Length / sizeof(char)];
        System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
        return new string(chars);
    }

    private bool Load(string fileName)
    {
     // Handle any problems that might arise when reading the text
     try
     {
         string line;
         // Create a new StreamReader, tell it which file to read and what encoding the file
         // was saved as
            StreamReader theReader = new StreamReader(Application.dataPath + "/Resources/" + fileName + ".txt");
         // Immediately clean up the reader after this block of code is done.
         // You generally use the "using" statement for potentially memory-intensive objects
         // instead of relying on garbage collection.
         // (Do not confuse this with the using directive for namespace at the 
         // beginning of a class!)
         using (theReader)
         {
             // While there's lines left in the text file, do this:
             do
             {
                 line = theReader.ReadLine();

                 if (line != null)
                 {
                     // Do whatever you need to do with the text line, it's a string now
                     // In this example, I split it into arguments based on comma
                     // deliniators, then send that array to DoStuff()
                     string[] entries = line.Split(':');
                     if (entries.Length > 0){
                            Settings newSetting = new Settings(entries[0], entries[1]);
                            settings.Add(newSetting);
                        }
                 }
             }
             while (line != null);
             // Done reading, close the reader and return true to broadcast success    
             theReader.Close();
             return true;
             }
         }
         // If anything broke in the try block, we throw an exception with information
         // on what didn't work
         catch (Exception e)
         {
             Console.WriteLine("{0}\n", e.Message);
             return false;
         }
     }
 }

Answer 1

necessary data rewind wasn't possible mainly occurs when redirection is involved during the WWW call.

To fix this, make sure that the URL's you call are not redirecting you to another page in the process. Also it would be a good idea to have some error handling before you use the value.

// wait for the result
yield return text;

// Handle the error if there is any
if (!string.IsNullOrEmpty(text.error)) {
    Debug.Log(text.error);
}
// Now do with POSTResponse whatever you want if there were no errors.