downloader.cs

飞信的收发使用csharp进行开发

namespace Imps.Client.Pc
{
    using Imps.Client.Base;
    using Imps.Client.Core;
    using System;
    using System.IO;
    using System.Net;
    using System.Runtime.CompilerServices;
    using System.Threading;

    internal class Downloader
    {
        private volatile bool _Downloading;
        private long _FileSize;
        private long _HasDownloadedSize;
        private DateTime _LastModified = DateTime.MinValue;
        private IWebProxy _WebProxy = WebRequest.DefaultWebProxy;
        public object DownloadLocker = new object();
        private const int MaxTryTimes = 10;

        public event EventHandler BeginDownload;

        public event EventHandler<EndDownloadedEventArgs> EndDownload;

        public event EventHandler<PartDownloadedEventArgs> PartDownloaded;

        public void Download(string url, string path)
        {
            bool isComplete = true;
            try
            {
                this._Downloading = true;
                this.RaiseBeginDownload();
                if (System.IO.File.Exists(path))
                {
                    System.IO.File.SetAttributes(path, FileAttributes.Normal);
                    System.IO.File.Delete(path);
                }
                string str = path + ".Downloading";
                if (!Directory.Exists(Path.GetDirectoryName(str)))
                {
                    Directory.CreateDirectory(Path.GetDirectoryName(str));
                }
                if (!System.IO.File.Exists(str))
                {
                    this._HasDownloadedSize = 0L;
                }
                else
                {
                    long length = new FileInfo(str).Length;
                    if (this._HasDownloadedSize > length)
                    {
                        this._HasDownloadedSize = 0L;
                        System.IO.File.Delete(str);
                    }
                    else if (this._HasDownloadedSize < length)
                    {
                        this._HasDownloadedSize = length;
                        using (FileStream stream = new FileStream(str, FileMode.Open, FileAccess.Write))
                        {
                            stream.SetLength(this._HasDownloadedSize);
                            this.RaisePartDownloadedEvent(this._HasDownloadedSize);
                        }
                    }
                }
                FileStream stream2 = new FileStream(str, FileMode.Append, FileAccess.Write, FileShare.None);
                try
                {
                    HttpWebRequest request = ConnectionFactory.CreateHttpWebRequest(url, null, false, false);
                    if (this.HasDownloadedSize > 0L)
                    {
                        request.AddRange((int) this.HasDownloadedSize);
                    }
                    HttpWebResponse response = null;
                    int num2 = 0;
                    while (true)
                    {
                        try
                        {
                            response = (HttpWebResponse) request.GetResponse();
                            break;
                        }
                        catch (WebException exception)
                        {
                            if (num2 >= 10)
                            {
                                throw;
                            }
                            if (exception.Response == null)
                            {
                                throw;
                            }
                            if ((exception.Response as HttpWebResponse).StatusCode != HttpStatusCode.RequestTimeout)
                            {
                                throw;
                            }
                        }
                        catch (Exception)
                        {
                            throw;
                        }
                        num2++;
                    }
                    using (HttpWebResponse response3 = response)
                    {
                        int statusCode = (int) response.StatusCode;
                        if ((statusCode < 200) || (statusCode > 0x12b))
                        {
                            throw new DownloadException(string.Empty, statusCode);
                        }
                        if (statusCode == 0xcc)
                        {
                            stream2.Close();
                            System.IO.File.Delete(str);
                            return;
                        }
                        using (Stream stream3 = response.GetResponseStream())
                        {
                            byte[] buffer = new byte[0xc800];
                            try
                            {
                                int num4;
                                while ((num4 = stream3.Read(buffer, 0, buffer.Length)) > 0)
                                {
                                    lock (this.DownloadLocker)
                                    {
                                        stream2.Write(buffer, 0, num4);
                                        this._HasDownloadedSize = stream2.Length;
                                    }
                                    this.RaisePartDownloadedEvent((long) num4);
                                }
                            }
                            finally
                            {
                                this._HasDownloadedSize = stream2.Length;
                                this.RaisePartDownloadedEvent(0L);
                            }
                        }
                    }
                }
                catch (DownloadException)
                {
                    isComplete = false;
                    throw;
                }
                catch (WebException exception2)
                {
                    isComplete = false;
                    HttpWebResponse response2 = exception2.Response as HttpWebResponse;
                    throw new DownloadException(exception2.Message + "\tUrl:" + url, (response2 == null) ? ((int) ((HttpStatusCode) 0)) : ((int) response2.StatusCode), exception2);
                }
                catch (ThreadAbortException)
                {
                    isComplete = true;
                    throw;
                }
                catch (Exception exception3)
                {
                    isComplete = false;
                    throw new DownloadException(exception3.Message + "\tUrl:" + url, exception3);
                }
                finally
                {
                    if (stream2 != null)
                    {
                        stream2.Dispose();
                    }
                }
                System.IO.File.Move(str, path);
            }
            finally
            {
                this._Downloading = false;
                this.RaiseEndDownload(isComplete);
            }
        }

        private void RaiseBeginDownload()
        {
            FuncDispatcher.InvokeEventHandlerInUiThread(this, this.BeginDownload, null);
        }

        private void RaiseEndDownload(bool isComplete)
        {
            FuncDispatcher.InvokeEventHandlerInUiThread<EndDownloadedEventArgs>(this, this.EndDownload, new EndDownloadedEventArgs(isComplete));
        }

        private void RaisePartDownloadedEvent(long size)
        {
            FuncDispatcher.InvokeEventHandlerInUiThread<PartDownloadedEventArgs>(this, this.PartDownloaded, new PartDownloadedEventArgs(size));
        }

        public bool Downloading
        {
            get
            {
                return this._Downloading;
            }
        }

        public long FileSize
        {
            get
            {
                return this._FileSize;
            }
            set
            {
                if (this.Downloading)
                {
                    throw new DownloadException("在下载过程中更改了文件大小");
                }
                if (value < 0L)
                {
                    throw new DownloadException("设置了小于零的字节数");
                }
                this._FileSize = value;
            }
        }

        public long HasDownloadedSize
        {
            get
            {
                return this._HasDownloadedSize;
            }
            set
            {
                if (this.Downloading)
                {
                    throw new DownloadException("在下载过程中更改了已下载字节大小");
                }
                if (value < 0L)
                {
                    throw new ArgumentException("设置了小于零的已下载字节大小");
                }
                this._HasDownloadedSize = value;
            }
        }

        public DateTime LastModified
        {
            get
            {
                return this._LastModified;
            }
            set
            {
                if (this.Downloading)
                {
                    throw new DownloadException("在下载过程中更改了上次修改时间");
                }
                this._LastModified = value;
            }
        }

        public IWebProxy WebProxy
        {
            get
            {
                return this._WebProxy;
            }
            set
            {
                this._WebProxy = value;
            }
        }
    }
}