using UnityEngine;
using System.Collections;
using System;
using System.Text;
using System.Net;
using System.IO;internal class WebReqState
{public byte[] Buffer;public FileStream fs;public const int BufferSize = 1024;public Stream OrginalStream;public HttpWebResponse WebResponse;public WebReqState(string path){Buffer = new byte[1024];fs = new FileStream(path,FileMode.Create);}}public class HttpHelper {string path = null;string assetName;public HttpHelper(string path){this.path = path;}public  void AsyDownLoad(string url)
{Debug.Log(url);assetName = url.Split('/')[4];Debug.Log(assetName);HttpWebRequest httpRequest = WebRequest.Create(url) as HttpWebRequest;httpRequest.BeginGetResponse( new AsyncCallback(ResponseCallback), httpRequest);
}void ResponseCallback(IAsyncResult ar)
{HttpWebRequest req = ar.AsyncState as HttpWebRequest;if(req == null) return;HttpWebResponse response = req.EndGetResponse(ar) as HttpWebResponse;if(response.StatusCode != HttpStatusCode.OK){response.Close();return;}Debug.Log(path+ "/"+assetName);WebReqState st = new WebReqState(path+ "/"+assetName);st.WebResponse = response;Stream responseStream = response.GetResponseStream();st.OrginalStream = responseStream;responseStream.BeginRead(st.Buffer,0,WebReqState.BufferSize,new AsyncCallback(ReadDataCallback),st);
}void ReadDataCallback(IAsyncResult ar)
{WebReqState rs = ar.AsyncState as WebReqState;int read =rs.OrginalStream.EndRead(ar);if(read>0){rs.fs.Write(rs.Buffer,0,read);rs.fs.Flush();rs.OrginalStream.BeginRead(rs.Buffer, 0, WebReqState.BufferSize, new AsyncCallback(ReadDataCallback), rs);}else{rs.fs.Close();rs.OrginalStream.Close();rs.WebResponse.Close();Debug.Log(assetName+":::: success");}
}
}