ASP.NET中下載檔案

//TransmitFile實現下載

protected void Button1_Click(object sender, EventArgs e)

{

/*

微軟為Response物件提供了一個新的方法TransmitFile來解決使用Response.BinaryWrite

下載超過400mb的檔案時導致Aspnet_wp.exe程式回收而無法成功下載的問題。

程式碼如下：

*/

Response.ContentType = "application/x-zip-compressed";

Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");

string filename = Server.MapPath("DownLoad/z.zip");

Response.TransmitFile(filename);

}

//WriteFile實現下載

protected void Button2_Click(object sender, EventArgs e)

{

/*

using System.IO;

*/

string fileName = "asd.txt";//客戶端儲存的檔名

string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑

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分塊下載

protected void Button3_Click(object sender, EventArgs e)

{

string fileName = "aaa.txt";//客戶端儲存的檔名

string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑

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

if (fileInfo.Exists == true)

{

const long ChunkSize = 102400;//100K 每次讀取檔案，只讀取100K，這樣可以緩解伺服器的壓力

byte[] buffer = new byte[ChunkSize];

Response.Clear();

System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);

long dataLengthToRead = iStream.Length;//獲取下載的檔案總大小

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));//讀取的大小

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

Response.Flush();

dataLengthToRead = dataLengthToRead - lengthRead;

}

Response.Close();

}

}

//流方式下載

protected void Button4_Click(object sender, EventArgs e)

{

string fileName = "aaa.txt";//客戶端儲存的檔名

string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑

//以字元流的形式下載檔案

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";

//通知瀏覽器下載檔案而不是開啟

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

Response.BinaryWrite(bytes);

Response.Flush();

Response.End();

}

//----------------------------------------------------------

public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody )

{

　　WebForm.Response.ClearHeaders();

　　WebForm.Response.Clear();

　　WebForm.Response.Expires = 0;

　　WebForm.Response.Buffer = true;

　　WebForm.Response.AddHeader("Accept-Language", "zh-tw");

　　//'檔名稱

　　WebForm.Response.AddHeader("content-disposition", "attachment; filename='"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"'");

　　WebForm.Response.ContentType = "Application/octet-stream";

　　//'檔案內容

　　WebForm.Response.Write(FileBody);//-----------

WebForm.Response.End();

}

//上面這段程式碼是下載一個動態產生的文字檔案，若這個檔案已經存在於伺服器端的實體路徑，則可以透過下面的函式：

public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath )

{

　　WebForm.Response.ClearHeaders();

　　WebForm.Response.Clear();

　　WebForm.Response.Expires = 0;

WebForm.Response.Buffer = true;

　　WebForm.Response.AddHeader("Accept-Language", "zh-tw");

　　//檔名稱

　　WebForm.Response.AddHeader("content-disposition", "attachment; filename='" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"'" );

　　WebForm.Response.ContentType = "Application/octet-stream";

　　//檔案內容

　　WebForm.Response.Write(System.IO.File.ReadAllBytes(FilePath));//---------

　　WebForm.Response.End();

}