C# 通过地址获取文件及名称（含后缀）

通过两种方式：

HttpWebRequest 

WebClient

废话不多说，直接上代码

        /// <summary>
        /// 通过地址获取文件及名称（含后缀）
        /// </summary>
        /// <param name="url">文件下载地址</param>
        /// <param name="stream">文件流</param>
        public static string GetFileName(string url, out Stream stream)
        {
            string fileName = string.Empty;
            stream = null;

            // 方式1 ： HttpWebRequest
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.KeepAlive = false;
            request.AllowAutoRedirect = false;
            request.Timeout = 10000;
            request.ContentType = "application/x-www-form-urlencoded;charset=utf-8";
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                if (response.StatusCode == HttpStatusCode.OK || response.StatusCode == HttpStatusCode.PartialContent)//返回为200或206
                {
                    var contentDescriptionHeader = response.GetResponseHeader("Content-Disposition");

                    if (!string.IsNullOrEmpty(contentDescriptionHeader))
                    {
                        System.Net.Mime.ContentDisposition contentDisposition = new System.Net.Mime.ContentDisposition(contentDescriptionHeader);
                        fileName = contentDisposition.FileName;

                        //正则表达式的方式获取
                        //fileName = System.Text.RegularExpressions.Regex.Match(contentDescriptionHeader, @"(?<=filename="")([\s\S]+)(?="")", System.Text.RegularExpressions.RegexOptions.IgnoreCase).Value;
                    }

                    stream = response.GetResponseStream();
                }
            }

            // 方式2 ：WebClient
            using (var client = new WebClient())
            {
                //client.OpenRead(url);

                var data = client.DownloadData(url);

                var contentDescriptionHeader = client.ResponseHeaders["Content-Disposition"].ToString();

                if (!string.IsNullOrEmpty(contentDescriptionHeader))
                {
                    System.Net.Mime.ContentDisposition contentDisposition = new System.Net.Mime.ContentDisposition(contentDescriptionHeader);
                    fileName = contentDisposition.FileName;

                    //正则表达式的方式获取
                    //fileName = System.Text.RegularExpressions.Regex.Match(contentDescriptionHeader, @"(?<=filename="")([\s\S]+)(?="")", System.Text.RegularExpressions.RegexOptions.IgnoreCase).Value;
                }

                foreach (var b in data)
                {
                    stream.WriteByte(b);
                }
            }

            return fileName;
        }