先列出代码，过段时间再写说明
protected void Page_Load(object sender, EventArgs e) { string strUrl = "http://"; SaveFile(strUrl); } private void SaveFile(string url) { int blocksize = 1024 * 100; byte[] buffer = new byte[blocksize]; string strFileName = @"D:\temp\1.pdf"; WebRequest request = WebRequest.Create(url); WebResponse response = request.GetResponse(); Stream reader = response.GetResponseStream(); FileStream writer = new FileStream(strFileName, FileMode.OpenOrCreate, FileAccess.Write); int c = 0; while ((c = reader.Read(buffer, 0, buffer.Length)) > 0) { writer.Write(buffer, 0, c); } writer.Close(); writer.Dispose(); reader.Close(); reader.Dispose(); response.Close(); } #region 下载并保存文件 public static bool SaveDownloadFile(string strUrl, string strFilePath, string strFileName) { if (!CreateDirectory(strFilePath)) return false; bool bResult = false; int blocksize = 1024 * 100; byte[] buffer = new byte[blocksize]; string strFileFullName = strFilePath + strFileName; WebRequest request = null; WebResponse response = null; Stream reader = null; FileStream writer = null; try { request = WebRequest.Create(strUrl); response = request.GetResponse(); reader = response.GetResponseStream(); writer = new FileStream(strFileFullName, FileMode.OpenOrCreate, FileAccess.Write); int c = 0; while ((c = reader.Read(buffer, 0, buffer.Length)) > 0) { writer.Write(buffer, 0, c); } bResult = true; } catch { } finally { if (writer != null) { writer.Close(); writer.Dispose(); } if (reader != null) { reader.Close(); reader.Dispose(); } if(response != null) response.Close(); if (request != null) request = null; } return bResult; } #endregion