asp.net中实现文件下载功能

//TransmitFile实现下载
protected
void Button1_Click(object
sender, EventArgs e)
{

Response.ContentType
= "application/x-zip-compressed";
Response.AddHeader("Content-Disposition",
"attachment;filename=z.zip");
string
filename =
Server.MapPath("DownLoad/aaa.zip");
Response.TransmitFile(filename);
}

//WriteFile实现下载
protected
void Button2_Click(object
sender, EventArgs e)
{

string
fileName ="aaa.zip";//客户端保存的文件名
string
filePath=Server.MapPath("DownLoad/aaa.zip");//路径

FileInfo fileInfo
= new FileInfo(filePath);
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.AddHeader("Content-Disposition",
"attachment;filename="
+ fileName);
Response.AddHeader("Content-Length", fileInfo.Length.ToString());
Response.AddHeader("Content-Transfer-Encoding",
"binary");
Response.ContentType
= "application/octet-stream";
Response.ContentEncoding
= System.Text.Encoding.GetEncoding("gb2312");
Response.WriteFile(fileInfo.FullName);
Response.Flush();
Response.End();
}

//WriteFile分块下载
protected
void Button3_Click(object
sender, EventArgs e)
{

string
fileName =
"aaa.zip";//客户端保存的文件名
string
filePath =
Server.MapPath("DownLoad/aaa.zip");//路径

System.IO.FileInfo fileInfo
= new System.IO.FileInfo(filePath);

if
(fileInfo.Exists ==
true)
{
const
long ChunkSize
= 102400;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力
byte[] buffer
= new
byte[ChunkSize];

Response.Clear();
System.IO.FileStream iStream
= System.IO.File.OpenRead(filePath);
long
dataLengthToRead =
iStream.Length;//获取下载的文件总大小
Response.ContentType
= "application/octet-stream";
Response.AddHeader("Content-Disposition",
"attachment; filename="
+ HttpUtility.UrlEncode(fileName));
while
(dataLengthToRead
> 0 &&
Response.IsClientConnected)
{
int
lengthRead =
iStream.Read(buffer,
0, Convert.ToInt32(ChunkSize));//读取的大小
Response.OutputStream.Write(buffer,
0, lengthRead);
Response.Flush();
dataLengthToRead
= dataLengthToRead
- lengthRead;
}
Response.Close();
}
}

//流方式下载
protected
void Button4_Click(object
sender, EventArgs e)
{
string
fileName =
"aaa.zip";//客户端保存的文件名
string
filePath =
Server.MapPath("DownLoad/aaa.zip");//路径

//以字符流的形式下载文件
FileStream fs
= new
FileStream(filePath, FileMode.Open);
byte[] bytes
= new
byte[(int)fs.Length];
fs.Read(bytes,
0, bytes.Length);
fs.Close();
Response.ContentType
= "application/octet-stream";
//通知浏览器下载文件而不是打开
Response.AddHeader("Content-Disposition",
"attachment; filename="
+ HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();

}

文件上传功能

public noticia AddFile(noticia noticiaToAdd, HttpPostedFileBase file)
{
string urlDirArquivo = "/upload/arquivonoticia";
string fileName = Path.GetFileName(file.FileName);
string urlArquivo = string.Format("{0}/{1}", urlDirArquivo, fileName);
string dirpath = HttpContext.Current.Server.MapPath(urlDirArquivo);
string filePath = Path.Combine(dirpath, fileName);
file.SaveAs(filePath);

arquivonoticia arquivoNoticia = new arquivonoticia();
arquivoNoticia.Id = Guid.NewGuid().ToString();
arquivoNoticia.Nome = fileName;
arquivoNoticia.Url = urlArquivo;

var noticiaOriginal = GetNoticia(noticiaToAdd.Id);

arquivoNoticia.noticiasReference.Value = noticiaOriginal;

noticiaOriginal.arquivonoticia.Add(arquivoNoticia) ;

_entities.SaveChanges();

return noticiaToAdd;
}