在Asp.net里可能会用到让客户下载文件的操作：
/// <summary>
/// 客户下载文件 /// </summary>
/// <param name="fileName">服务器源文件物理地址</param>
private void DownloadFile(string fileName) ...{ string saveFile = System.IO.Path.GetFileName(fileName); string extName = System.IO.Path.GetExtension(fileName); string defaultType = "application/unknown"; RegistryKey rootKey, extKey; string contentType; try
...{ rootKey = Registry.ClassesRoot; extKey = rootKey.OpenSubKey(extName); contentType = extKey.GetValue("Content Type", defaultType).ToString();
} catch ...{ contentType = defaultType; } Response.Clear(); Response.Buffer = true; Response.AppendHeader("Content-Disposition", "attachment;filename=" + saveFile); Response.ContentType = contentType; Response.WriteFile(fileName); Response.Flush(); Response.Close(); }方法来源于这个地址：http://www.itlearner.com/article/2005/2375.shtml
觉得文章的作者写的很不错，为了记录这个方法特在些做个备份以便以后查阅！