JunShi101ShiNei/Assets/XDKUnityPluginCloud/Editor/SeengeneMapConfig/EditorDownloadObject.cs

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

public class EditorDownloadObject {

    private string m_DownloadURL;
    private string m_LocalFilePath;
    private Action m_CallBack;

    //下载进度
    public float progress { get; private set; }

    //涉及子线程要注意,Unity关闭的时候子线程不会关闭，所以要有一个标识
    private bool isStop;

    //表示下载是否完成
    public bool isDone { get; private set; }
    public long currentFileLength { get; private set; }
    public long totalFileLength { get; private set; }

    const int ReadWriteTimeOut = 2 * 1000;//超时等待时间
    const int TimeOutWait = 120 * 1000;//超时等待时间

    private Thread thread;
    FileStream fileStream;
    Stream stream;

    /// <summary>
    /// 下载方法(断点续传)
    /// </summary>
    /// <param name="url">URL下载地址</param>
    /// <param name="savePath">Save path保存路径</param>
    /// <param name="m_path">模型bundle保存路径</param>
    /// <param name="callBack">Call back回调函数</param>
    public void DownLoad(string url, string savePath, Action callBack) {
        isStop = false;
        m_DownloadURL = url;
        m_LocalFilePath = savePath;
        m_CallBack = callBack;

        //开启子线程
        thread = new Thread(DownloadInternal);
        thread.IsBackground = true;
        thread.Start();
    }

    private void DownloadInternal() {
        fileStream = new FileStream(m_LocalFilePath, FileMode.OpenOrCreate, FileAccess.Write);
        currentFileLength = fileStream.Length;
        totalFileLength = GetTotalFileLength(m_DownloadURL);

        if (currentFileLength < totalFileLength) {
            //断点续传核心，设置本地文件流的起始位置
            fileStream.Seek(currentFileLength, SeekOrigin.Begin);
            ServicePointManager.DefaultConnectionLimit = 200;
            HttpWebRequest request = HttpWebRequest.Create(m_DownloadURL) as HttpWebRequest;
            request.UseDefaultCredentials = false;
            request.Proxy = null;
            request.CachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.NoCacheNoStore);
            request.ReadWriteTimeout = ReadWriteTimeOut;
            request.Timeout = TimeOutWait;
            request.KeepAlive = false;

            //断点续传核心，设置远程访问文件流的起始位置
            request.AddRange((int)currentFileLength);
            WebResponse response = request.GetResponse();
            stream = response.GetResponseStream();
            byte[] buffer = new byte[1024];
            //使用流读取内容到buffer中
            int length = stream.Read(buffer, 0, buffer.Length);
            while (length > 0) {
                //如果Unity客户端关闭，停止下载
                if (isStop) {
                    break;
                }
                fileStream.Write(buffer, 0, length);
                currentFileLength += length;
                progress = (float)currentFileLength / (float)totalFileLength;
                length = stream.Read(buffer, 0, buffer.Length);

            }
            stream.Close();
            stream.Dispose();
        } else {
            progress = 1;
        }
        fileStream.Close();
        fileStream.Dispose();
        //如果下载完毕，执行回调
        if (progress == 1) {
            isDone = true;
            if (m_CallBack != null) m_CallBack();
            Debug.Log("download finished");
        }
        thread.Abort();
    }

    /// <summary>
    /// 获取下载文件的大小
    /// </summary>
    /// <returns>The length.</returns>
    /// <param name="url">URL.</param>
    long GetTotalFileLength(string url) {
        HttpWebRequest requet = HttpWebRequest.Create(url) as HttpWebRequest;
        requet.Method = "HEAD";
        HttpWebResponse response = requet.GetResponse() as HttpWebResponse;
        return response.ContentLength;
    }

    public void Dispose() {
        isStop = true;
        if (fileStream != null) {
            fileStream.Close();
            fileStream.Dispose();
        }
        if (stream != null) {
            stream.Close();
            stream.Dispose();
        }
        if (thread != null) {
            thread.Abort();
        }
        Debug.LogFormat("EditorDownloadObject.Dispose: {0}", m_DownloadURL);
    }
}