How to download files from web url ?

Hello,

Actually, i have a website url where these files are stored. Example:
http://www.mywebsite.com/files/file.txt
http://www.mywebsite.com/files/image1.gif
http://www.mywebsite.com/files/logo.jpg
http://www.mywebsite.com/files/letter.doc
http://www.mywebsite.com/files/dll/barcode.dll
http://www.mywebsite.com/files/dll/MyLib.dll
http://www.mywebsite.com/files/dll/Common.dll
http://www.mywebsite.com/files/exe/MyApp.exe
etc...

So, my target is to build a small Device Application (Windows CE) in order to update these files on the device itself everytime the user clicked Update button.

So I would like to download the content of the main folder http://www.mywebsite.com/files/ as is (e.g. with all files & sub-folders) on the device.

Please, can anyone help me to know how to connect to the URL and download the list of files ?

I really appreciate if you can give me a sample code

Paul

Hi,

Following approaches can be used to achieve it using ASP.Net and C#:

1) If file is in the same web server where web application or website is running:

a) You can just add a link to the file to be downloaded. Use following code in your ASP.Net page:

Download

When user click on the link, either file will be opened directly in the web browser (if the plug-in for the downloaded file is installed) or user will be prompted to Open/Save the file. But I felt this approach is a static method and aslo not very secure.

b) The second approach to do this is a dynamic method i.e. programmatically downloading a file from web server to client. First add a LinkButton in your Asp.Net page, use following code snippet:

Download

Now go to code behid file of the ASP.Net page and write following C# code in the Click event of the LinkButton:

protected void _lbtDownload_Click(object sender, EventArgs e)

{

HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create("http://www.SiteName.com/Downloads/Sample.zip");

HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();

int bufferSize = 1;

Response.Clear();

Response.ClearHeaders();

Response.ClearContent();

Response.AppendHeader("Content-Disposition:", "attachment; filename=Sample.zip");

Response.AppendHeader("Content-Length", objResponse.ContentLength.ToString());

Response.ContentType = "application/download";

byte[] byteBuffer = new byte[bufferSize + 1];

MemoryStream memStrm = new MemoryStream(byteBuffer, true);

Stream strm = objRequest.GetResponse().GetResponseStream();

byte[] bytes = new byte[bufferSize + 1];

while (strm.Read(byteBuffer, 0, byteBuffer.Length) > 0)

{

Response.BinaryWrite(memStrm.ToArray());

Response.Flush();

}

Response.Close();

Response.End();

memStrm.Close();

memStrm.Dispose();

strm.Dispose();

}

When user will click on LinkButton, above code will be executed which will download the "Sample.zip" file to the user's computer.

2) If file is in the remote file server: In this case, the same code as in above section 1(a) can be used with little modifications. First add a LinkButton in your Asp.Net page, use following code snippet:

Download

Now again go to code behid file of the ASP.Net page and write following C# code in the Click event of the LinkButton:

protected void _lbtDownload_Click(object sender, EventArgs e)

{

FileInfo file = new FileInfo(@"\\RemoteServerIP_OR_Name\FolderName\Sample.zip");

Response.Clear();

Response.ClearHeaders();

Response.ClearContent();

Response.AppendHeader("Content-Disposition", "attachment; filename = Sample.zip");

Response.AppendHeader("Content-Length", file.Length.ToString());

Response.ContentType = "application/download";

Response.WriteFile(file.FullName);

Response.Flush();

Response.Close();

Response.End();

}

Note: Please make sure that the user ID under which your web application or website is running must have atleast read access to the remote file server.

References:
http://www.etechplanet.com/blog/downloading-file-using-aspnet-and-c.aspx
http://www.west-wind.com/weblog/posts/2007/May/21/Downloading-a-File-with-a-Save-As-Dialog-in-ASPNET

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Senthilkumar14y ago
Hi,

Following approaches can be used to achieve it using ASP.Net and C#:

1) If file is in the same web server where web application or website is running:

a) You can just add a link to the file to be downloaded. Use following code in your ASP.Net page:

Download
OR
Download

When user click on the link, either file will be opened directly in the web browser (if the plug-in for the downloaded file is installed) or user will be prompted to Open/Save the file. But I felt this approach is a static method and aslo not very secure.

b) The second approach to do this is a dynamic method i.e. programmatically downloading a file from web server to client. First add a LinkButton in your Asp.Net page, use following code snippet:

Download

Now go to code behid file of the ASP.Net page and write following C# code in the Click event of the LinkButton:

protected void _lbtDownload_Click(object sender, EventArgs e)
{
HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create("http://www.SiteName.com/Downloads/Sample.zip");
HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
int bufferSize = 1;
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.AppendHeader("Content-Disposition:", "attachment; filename=Sample.zip");
Response.AppendHeader("Content-Length", objResponse.ContentLength.ToString());
Response.ContentType = "application/download";
byte[] byteBuffer = new byte[bufferSize + 1];
MemoryStream memStrm = new MemoryStream(byteBuffer, true);
Stream strm = objRequest.GetResponse().GetResponseStream();
byte[] bytes = new byte[bufferSize + 1];
while (strm.Read(byteBuffer, 0, byteBuffer.Length) > 0)
{
Response.BinaryWrite(memStrm.ToArray());
Response.Flush();
}
Response.Close();
Response.End();
memStrm.Close();
memStrm.Dispose();
strm.Dispose();
}

When user will click on LinkButton, above code will be executed which will download the "Sample.zip" file to the user's computer.

2) If file is in the remote file server: In this case, the same code as in above section 1(a) can be used with little modifications. First add a LinkButton in your Asp.Net page, use following code snippet:

Download

Now again go to code behid file of the ASP.Net page and write following C# code in the Click event of the LinkButton:

protected void _lbtDownload_Click(object sender, EventArgs e)
{
FileInfo file = new FileInfo(@"\\RemoteServerIP_OR_Name\FolderName\Sample.zip");
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.AppendHeader("Content-Disposition", "attachment; filename = Sample.zip");
Response.AppendHeader("Content-Length", file.Length.ToString());
Response.ContentType = "application/download";
Response.WriteFile(file.FullName);
Response.Flush();
Response.Close();
Response.End();
}

Note: Please make sure that the user ID under which your web application or website is running must have atleast read access to the remote file server.

References:
http://www.etechplanet.com/blog/downloading-file-using-aspnet-and-c.aspx
http://www.west-wind.com/weblog/posts/2007/May/21/Downloading-a-File-with-a-Save-As-Dialog-in-ASPNET

0
Bryian Tan14y ago
hello,

Have you try to use WebRequest and WebResponse Classes ? Here are few examples.

http://www.codeguru.com/columns/dotnettips/article.php/c7005/Downloading-Files-with-the-WebRequest-and-WebResponse-Classes.htm

http://code.msdn.microsoft.com/CSASPNETRemoteUploadAndDown-a80b7cb5
0