C#同步、异步远程下载文件实例

1、使用HttpWebRequest/HttpWebResonse和WebClient

if (!response.ContentType.ToLower().StartsWith("text/"))
{
    //Value = SaveBinaryFile(response, FileName);
    byte[] buffer = new byte[1024];
    Stream outStream = System.IO.File.Create(FileName);
    Stream inStream = response.GetResponseStream();

    int l;
    do
    {
        l = inStream.Read(buffer, 0, buffer.Length);
        if (l > 0)
            outStream.Write(buffer, 0, l);
    }
    while (l > 0);

    outStream.Close();
    inStream.Close();
}
</div>

2、使用WebClient

3、异步下载例子

            #region 分析计时开始

            count = 0;
            count1 = 0;
            freq = 0;
            result = 0;

            QueryPerformanceFrequency(ref freq);
            QueryPerformanceCounter(ref count);

            #endregion

            using (WebClient wClient = new WebClient())
            {
                AutoResetEvent waiter = new AutoResetEvent(false);
                wClient.Credentials = CredentialCache.DefaultCredentials;
                wClient.DownloadDataCompleted += new DownloadDataCompletedEventHandler(AsyncURIAnalyze);
                wClient.DownloadDataAsync(new Uri(uriString), waiter);
                waiter.WaitOne();    阻止当前线程，直到收到信号
            }

        }

        ///summary
        ///异步分析
        ///summary
        protected void AsyncURIAnalyze(Object sender, DownloadDataCompletedEventArgs e)
        {
            AutoResetEvent waiter = (AutoResetEvent)e.UserState;
            try
            {
                if (!e.Cancelled && e.Error == null)
                {

                    string dnDir = string.Empty;
                    string domainName = string.Empty;
                    string uri = uriString;

                    获得域名 [url]httpwww.sina.com[url]
                    Match match = Regex.Match(uri, @((http(s)))+[w-.]+[^]);, RegexOptions.IgnoreCase
                    domainName = match.Value;

                    获得域名最深层目录 [url]httpwww.sina.commail[url]
                    if (domainName.Equals(uri))
                        dnDir = domainName;
                    else
                        dnDir = uri.Substring(0, uri.LastIndexOf(''));

                    dnDir += '';

                    获取数据
                    string pageData = Encoding.UTF8.GetString(e.Result);
                    Liststring urlList = new Liststring();

                    匹配全路径
                    match = Regex.Match(pageData, @((http(s)))+((()+[w-.]+()))+[w-.]+.+( + ImageType + )); , RegexOptions.IgnoreCase
       &n