WebClient HttpWebRequest 下载文件到本地

 

处理方式：

第一种：  我们需要获取文件，但是我们不需要保存源文件的名称

        public void DownFile(string uRLAddress, string localPath, string filename)
        {
            WebClient client = new WebClient();
            Stream str = client.OpenRead(uRLAddress);
            StreamReader reader = new StreamReader(str);
            byte[] mbyte = new byte[1000000];
            int allmybyte = (int)mbyte.Length;
            int startmbyte = 0;

            while (allmybyte > 0)
            {

                int m = str.Read(mbyte, startmbyte, allmybyte);
                if (m == 0)
                {
                    break;
                }
                startmbyte += m;
                allmybyte -= m;
            }

            reader.Dispose();
            str.Dispose();

            //string paths = localPath + System.IO.Path.GetFileName(uRLAddress);
            string path = localPath + filename;
            FileStream fstr = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
            fstr.Write(mbyte, 0, startmbyte);
            fstr.Flush();
            fstr.Close();
        }

　　

第二种：我们需要获取文件，但是希望可以获取到文件的原名称以及其他的信息

　　　　/// <summary>
       /// 文件下载
       /// </summary>
       /// <param name="url">所下载的路径</param>
       /// <param name="path">本地保存的路径</param>
        /// <param name="overwrite">当本地路径存在同名文件时是否覆盖</param>
        /// <param name="callback">实时状态回掉函数</param>
        /// Action<文件名,文件的二进制, 文件大小, 当前已上传大小>
       public static void HttpDownloadFile(string url, string path, bool overwrite, Action<string,string, byte[], long, long> callback = null)
        {
            // 设置参数
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            //发送请求并获取相应回应数据
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //获取文件名
            string fileName = response.Headers["Content-Disposition"];//attachment;filename=FileName.txt
            string contentType = response.Headers["Content-Type"];//attachment;
           
            if (string.IsNullOrEmpty(fileName))
                fileName = response.ResponseUri.Segments[response.ResponseUri.Segments.Length - 1];
            else
                fileName = fileName.Remove(0, fileName.IndexOf("filename=") + 9);
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            using (Stream responseStream = response.GetResponseStream())
            {
                long totalLength = response.ContentLength;
                ///文件byte形式
                byte[] b = ImageHelper.ImageToByte1(url);
                //创建本地文件写入流
                if (System.IO.File.Exists(Path.Combine(path, fileName))) {
                    fileName = DateTime.Now.Ticks + fileName;
                }
                using (Stream stream = new FileStream(Path.Combine(path, fileName), overwrite ? FileMode.Create : FileMode.CreateNew))
                {
                    byte[] bArr = new byte[1024];
                    int size;
                    while ((size = responseStream.Read(bArr, 0, bArr.Length)) > 0)
                    {
                        stream.Write(bArr, 0, size);
                        callback.Invoke(fileName,contentType, b, totalLength, stream.Length);
                    }
                }
            }
        }

但是这并不是绝对的，第一种方法当地址是    ：  

http://128.1.3.67:8083/api/wap/v2/fs/image/d4cbc75704ece271a5e0f1765346587f.jpg 时我们一样可以获取到名称 

 

 使用：System.IO.Path.GetFileName(uRLAddress)