ASP.NET 实现Base64文件流下载PDF

因为业务需要调用接口获取的是 Base64文件流 需要提供给客户下载PDF文档

源码部分借鉴网上，具体地址忘记了。

 //Base64文件流

            byte[] buffer = Convert.FromBase64String(decodedString);

            System.IO.Stream iStream = new System.IO.MemoryStream(buffer);

            try

            {

                int length;

                long dataToRead;

                string filename = sn + ".pdf";//保存的文件名称

                dataToRead = iStream.Length;

                Response.Clear();

                Response.ClearHeaders();

                Response.ClearContent();

                Response.ContentType = "application/pdf"; //文件类型

                Response.AddHeader("Content-Length", dataToRead.ToString());//添加文件长度，进而显示进度

                Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));

                while (dataToRead > 0)

                {

                    if (Response.IsClientConnected)

                    {

                        length = iStream.Read(buffer, 0, 10000);

                        Response.OutputStream.Write(buffer, 0, length);

                        Response.Flush();

                        buffer = new Byte[10000];

                        dataToRead = dataToRead - length;

                    }

                    else

                    {

                        dataToRead = -1;

                    }

                }

            }

            catch (Exception ex)

            {

                Response.Write("文件下载时出现错误!");

            }

            finally

            {

                if (iStream != null)

                {

                    iStream.Close();

                }

                //结束响应，否则将导致网页内容被输出到文件，进而文件无法打开

                Response.Flush();

                Response.End();

            }