在unity 中，使用http请求，下载文件到可读可写路径

在这里我用了一个线程池，线程池参数接收一个带有object参数的，无返回值的委托，下载用到的核心代码，网上拷贝的，他的核心就是发起一个web请求，然后得到请求的响应，读取响应的流

剩下的都是常见的IO操作

由于线程池接参数的委托，接收一个object参数。所以，我把请求地址和本地存放地址以及名字，封装了一个类，用来传参

这是下载工具代码，如下

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Net;
using UnityEngine;public class DownLoaderEnum
{public string url;public string path;public DownLoaderEnum(string URL, string PATH){url = URL;path = PATH;}
}public class HttpDownload
{/// <summary>/// http下载文件/// </summary>/// <param name="url">下载文件地址</param>/// <param name="path">文件存放地址，包含文件名</param>/// <returns></returns>public void HttpDownloader(object down){if (!Directory.Exists((down as DownLoaderEnum).path))Directory.CreateDirectory((down as DownLoaderEnum).path);string tempPath = System.IO.Path.GetDirectoryName((down as DownLoaderEnum).path) + @"\temp";System.IO.Directory.CreateDirectory(tempPath);  //创建临时文件目录string tempFile = tempPath + @"\" + System.IO.Path.GetFileName((down as DownLoaderEnum).path) + ".temp"; //临时文件if (System.IO.File.Exists(tempFile)){System.IO.File.Delete(tempFile);    //存在则删除}try{FileStream fs = new FileStream(tempFile, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);// 设置参数HttpWebRequest request = WebRequest.Create((down as DownLoaderEnum).url) as HttpWebRequest;//发送请求并获取相应回应数据HttpWebResponse response = request.GetResponse() as HttpWebResponse;//直到request.GetResponse()程序才开始向目标网页发送Post请求Stream responseStream = response.GetResponseStream();//创建本地文件写入流//Stream stream = new FileStream(tempFile, FileMode.Create);byte[] bArr = new byte[1024];int size = responseStream.Read(bArr, 0, (int)bArr.Length);while (size > 0){//stream.Write(bArr, 0, size);fs.Write(bArr, 0, size);size = responseStream.Read(bArr, 0, (int)bArr.Length);}//stream.Close();fs.Close();responseStream.Close();string suffixName = (down as DownLoaderEnum).url;int su = suffixName.LastIndexOf('/');suffixName = (down as DownLoaderEnum).path+suffixName.Substring(su);// Debug.LogError(suffixName);System.IO.File.Move(tempFile, suffixName);// return true;Debug.LogError("下载完成");}catch (Exception ex){Debug.LogError("错误==>>" + ex.Message);//return false;}}
}

　　这是测试代码

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using UnityEngine;public class NewBehaviourScript : MonoBehaviour {public string url = "http://dl172.80s.im:920/1802/[比得兔]剧场预告片/[比得兔]剧场预告片_hd.mp4";// Use this for initializationstring path = "";HttpDownload download = new HttpDownload();DownLoaderEnum down;private void Awake(){path = Application.streamingAssetsPath;//DirectoryInfo directory = new DirectoryInfo(path);//if (directory.Exists)//    directory.Create();//Debug.LogError(path);}// Use this for initializationvoid Start(){ThreadPool.SetMaxThreads(5, 5);down = new DownLoaderEnum(url, path);//请求url，存放地址，存放文件名}// Update is called once per framevoid Update(){if (Input.GetKeyDown(KeyCode.Space)){ThreadPool.QueueUserWorkItem(download.HttpDownloader, down);}}
}

可以看到，已经下载完成