文件下载时出现提示框不直接打开

//读取文件输出它

string strFile = "c://abc.doc";

FileStream fs = new FileStream(strFile, FileMode.Open);

byte[] bytes = new byte[(int)fs.Length];

fs.Read(bytes, 0, bytes.Length);

fs.Close();

Response.ContentType = "application/octet-stream";

Response.AddHeader("Content-Disposition",  "attachment;  filename="  +  HttpUtility.UrlEncode(File.Name));

Response.BinaryWrite(bytes);

Response.End();