在Unity iOS上发出HTTP请求的方法？

Question

我需要使用所有标准RESTful方法发送HTTP请求并访问请求正文以便使用它发送/接收JSON.我调查过,

WebRequest.HttpWebRequest

这几乎是完美的,但有些情况下,例如,如果服务器关闭,函数GetResponse可能需要几秒钟才能返回 - 因为它是一个同步方法 - 冻结该时段的应用程序.这个方法的异步版本,BeginGetResponse,似乎不是异步工作(在Unity中),因为它仍然冻结该时期的应用程序.

UnityEngine.WWW#

由于某些原因,只支持POST和GET请求 - 但我还需要PUT和DELETE(标准的RESTful方法),所以我没有进一步深入研究它.

的System.Threading

为了运行WebRequest.HttpWebRequest.GetResponse而不冻结应用程序,我研究了使用线程.线程似乎在编辑器中工作(但看起来非常不稳定 - 如果你在应用程序退出时不停止线程,即使你停止它也会永远在编辑器中运行),并且当构建到iOS设备时它会立即崩溃因为我尝试启动一个线程(我忘记写下错误,我现在无法访问它).

在本机iOS应用程序中运行线程,并使用Unity应用程序的桥接器

荒谬,甚至不会尝试这个.

UniWeb

这个.我想知道他们是如何管理它的.

这是我正在尝试的WebRequest.BeginGetResponse方法的示例,

// The RequestState class passes data across async calls.
public class RequestState
{
   const int BufferSize = 1024;
   public StringBuilder RequestData;
   public byte[] BufferRead;
   public WebRequest Request;
   public Stream ResponseStream;
   // Create Decoder for appropriate enconding type.
   public Decoder StreamDecode = Encoding.UTF8.GetDecoder();

   public RequestState()
   {
      BufferRead = new byte[BufferSize];
      RequestData = new StringBuilder(String.Empty);
      Request = null;
      ResponseStream = null;
   }     
}

public class WebRequester
{
    private void ExecuteRequest()
    {
        RequestState requestState = new RequestState();
        WebRequest request = WebRequest.Create("mysite");
        request.BeginGetResponse(new AsyncCallback(Callback), requestState);
    }

    private void Callback(IAsyncResult ar)
    {
      // Get the RequestState object from the async result.
      RequestState rs = (RequestState) ar.AsyncState;

      // Get the WebRequest from RequestState.
      WebRequest req = rs.Request;

      // Call EndGetResponse, which produces the WebResponse object
      //  that came from the request issued above.
      WebResponse resp = req.EndGetResponse(ar);
    }
}

...基于此:http://msdn.microsoft.com/en-us/library/86wf6409(v = vs.71).aspx

Answer 1

好的,我终于设法编写了自己的解决方案.我们基本上需要一个RequestState,一个Callback方法和一个TimeOut Thread.在这里我就复制什么是在UnifyCommunity做(现在叫unity3d维基).这是过时的代码,但比那里的更小,所以更方便在这里展示一些东西.现在我删除了(在unit3d wiki中)System.Action并且static性能和简单性:

用法

static public ThisClass Instance;
void Awake () {
    Instance = GetComponent<ThisClass>();
}
static private IEnumerator CheckAvailabilityNow () {
    bool foundURL;
    string checkThisURL = "http://www.example.com/index.html";
    yield return Instance.StartCoroutine(
        WebAsync.CheckForMissingURL(checkThisURL, value => foundURL = !value)
        );
    Debug.Log("Does "+ checkThisURL +" exist? "+ foundURL);
}

WebAsync.cs

using System;
using System.IO;
using System.Net;
using System.Threading;
using System.Collections;
using UnityEngine;

/// <summary>
///  The RequestState class passes data across async calls.
/// </summary>
public class RequestState
{
    public WebRequest webRequest;
    public string errorMessage;

    public RequestState ()
    {
        webRequest = null;
        errorMessage = null;
    }
}

public class WebAsync {
    const int TIMEOUT = 10; // seconds

    /// <summary>
    /// If the URLs returns 404 or connection is broken, it's missing. Else, we suppose it's fine.
    /// </summary>
    /// <param name='url'>
    /// A fully formated URL.
    /// </param>
    /// <param name='result'>
    /// This will bring 'true' if 404 or connection broken and 'false' for everything else.
    /// Use it as this, where "value" is a System sintaxe:
    /// value => your-bool-var = value
    /// </param>
    static public IEnumerator CheckForMissingURL (string url, System.Action<bool> result) {
        result(false);

        Uri httpSite = new Uri(url);
        WebRequest webRequest = WebRequest.Create(httpSite);

        // We need no more than HTTP's head
        webRequest.Method = "HEAD";
        RequestState requestState = new RequestState();

        // Put the request into the state object so it can be passed around
        requestState.webRequest = webRequest;

        // Do the actual async call here
        IAsyncResult asyncResult = (IAsyncResult) webRequest.BeginGetResponse(
            new AsyncCallback(RespCallback), requestState);

        // WebRequest timeout won't work in async calls, so we need this instead
        ThreadPool.RegisterWaitForSingleObject(
            asyncResult.AsyncWaitHandle,
            new WaitOrTimerCallback(ScanTimeoutCallback),
            requestState,
            (TIMEOUT *1000), // obviously because this is in miliseconds
            true
            );

        // Wait until the the call is completed
        while (!asyncResult.IsCompleted) { yield return null; }

        // Deal up with the results
        if (requestState.errorMessage != null) {
            if ( requestState.errorMessage.Contains("404") || requestState.errorMessage.Contains("NameResolutionFailure") ) {
                result(true);
            } else {
                Debug.LogWarning("[WebAsync] Error trying to verify if URL '"+ url +"' exists: "+ requestState.errorMessage);
            }
        }
    }

    static private void RespCallback (IAsyncResult asyncResult) {

        RequestState requestState = (RequestState) asyncResult.AsyncState;
        WebRequest webRequest = requestState.webRequest;

        try {
            webRequest.EndGetResponse(asyncResult);
        } catch (WebException webException) {
            requestState.errorMessage = webException.Message;
        }
    }

    static private void ScanTimeoutCallback (object state, bool timedOut)  { 
        if (timedOut)  {
            RequestState requestState = (RequestState)state;
            if (requestState != null) 
                requestState.webRequest.Abort();
        } else {
            RegisteredWaitHandle registeredWaitHandle = (RegisteredWaitHandle)state;
            if (registeredWaitHandle != null)
                registeredWaitHandle.Unregister(null);
        }
    }
}

Answer 2

我在 iOS 上使用了线程 - 我相信它是由于幽灵线程或其他原因而崩溃的。重新启动设备似乎已经解决了崩溃问题，因此我将仅将 WebRequest.HttpWebRequest 与线程一起使用。