System.Net.WebClient.DownloadFile doesn't work with http attachments

Hi,
I have an aspx page at the web server that provides PDF documents for smart
client applications.
Here is the code in aspx page that defines content type:
Response.ContentType = "application/octet-stream";
Response.AppendHeader("Content-Disposition",
"attachment;filename=test.pdf");
I tested the aspx page by using browser and it works just fine.
Now I need to receive that file by using the
System.Net.WebClient.DownloadFile. The problem is that DownloadFile method
returns the following exception:
"Unable to read data from the transport connection: The connection was
closed."
I tested the DownloadFile method to open a direct pdf file like the
following statement:
(new
System.Net.WebClient()).DownloadFile(http://localhost/test.pdf,"c:\\test.pdf
");
It works just fine.
How can I use System.Net.WebClient. DownloadFile to download http
attachments?
Any help would be apprecited,
AlanThe answer is in your question, but you may not recognize it.
An HTTP Request is for a single resource, identified by the URL of the
resource, or in the case of the WebClient, a URI plus a file descriptor. You
have an ASPX page that returns a file with a couple of special Response
Headers in it. Those Response Headers read:
Response.ContentType = "application/octet-stream";
> Response.AppendHeader("Content-Disposition",
"attachment;filename=test.pdf");
This header indicates that the client should prompt the client to make a
second request for the file descriptor specified (text.pdf), and that the
Content-Type of that file is binary.
So, what you have to do is read the Response Headers, and make a second
request for that file specified.
IETF RFC 1806 has a detailed explanation of this Response Header:
http://www.ietf.org/rfc/rfc1806.txt
HTH,
Kevin Spencer
Microsoft MVP
.Net Developer
A watched clock never boils.
"A.M-SG" <alanalan@.newsgroup.nospam> wrote in message
news:eY7l5Zu3FHA.1148@.tk2msftngp13.phx.gbl...
> Hi,
> I have an aspx page at the web server that provides PDF documents for
> smart
> client applications.
> Here is the code in aspx page that defines content type:
> Response.ContentType = "application/octet-stream";
> Response.AppendHeader("Content-Disposition",
> "attachment;filename=test.pdf");
> I tested the aspx page by using browser and it works just fine.
> Now I need to receive that file by using the
> System.Net.WebClient.DownloadFile. The problem is that DownloadFile method
> returns the following exception:
> "Unable to read data from the transport connection: The connection was
> closed."
> I tested the DownloadFile method to open a direct pdf file like the
> following statement:
> (new
> System.Net.WebClient()).DownloadFile(http://localhost/test.pdf,"c:\\test.p
df");
> It works just fine.
> How can I use System.Net.WebClient. DownloadFile to download http
> attachments?
> Any help would be apprecited,
> Alan
>

System.Net.WebClient.DownloadFile doesnt work with http attachments

Hi,

I have an aspx page at the web server that provides PDF documents for smart
client applications.

Here is the code in aspx page that defines content type:

Response.ContentType = "application/octet-stream";
Response.AppendHeader("Content-Disposition",
"attachment;filename=test.pdf");

I tested the aspx page by using browser and it works just fine.

Now I need to receive that file by using the
System.Net.WebClient.DownloadFile. The problem is that DownloadFile method
returns the following exception:

"Unable to read data from the transport connection: The connection was
closed."

I tested the DownloadFile method to open a direct pdf file like the
following statement:

(new
System.Net.WebClient()).DownloadFile(http://localhost/test.pdf,"c:\\test.pdf");

It works just fine.

How can I use System.Net.WebClient. DownloadFile to download http
attachments?

Any help would be apprecited,
AlanThe answer is in your question, but you may not recognize it.

An HTTP Request is for a single resource, identified by the URL of the
resource, or in the case of the WebClient, a URI plus a file descriptor. You
have an ASPX page that returns a file with a couple of special Response
Headers in it. Those Response Headers read:

Response.ContentType = "application/octet-stream";
> Response.AppendHeader("Content-Disposition",
"attachment;filename=test.pdf");

This header indicates that the client should prompt the client to make a
second request for the file descriptor specified (text.pdf), and that the
Content-Type of that file is binary.

So, what you have to do is read the Response Headers, and make a second
request for that file specified.

IETF RFC 1806 has a detailed explanation of this Response Header:

http://www.ietf.org/rfc/rfc1806.txt

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
A watched clock never boils.

"A.M-SG" <alanalan@.newsgroup.nospam> wrote in message
news:eY7l5Zu3FHA.1148@.tk2msftngp13.phx.gbl...
> Hi,
> I have an aspx page at the web server that provides PDF documents for
> smart
> client applications.
> Here is the code in aspx page that defines content type:
> Response.ContentType = "application/octet-stream";
> Response.AppendHeader("Content-Disposition",
> "attachment;filename=test.pdf");
> I tested the aspx page by using browser and it works just fine.
> Now I need to receive that file by using the
> System.Net.WebClient.DownloadFile. The problem is that DownloadFile method
> returns the following exception:
> "Unable to read data from the transport connection: The connection was
> closed."
> I tested the DownloadFile method to open a direct pdf file like the
> following statement:
> (new
> System.Net.WebClient()).DownloadFile(http://localhost/test.pdf,"c:\\test.pdf");
> It works just fine.
> How can I use System.Net.WebClient. DownloadFile to download http
> attachments?
> Any help would be apprecited,
> Alan

System.Security.Cryptography.CryptographicExceptio n:

Hi,

I have two web applications running on my machine.The
application is developed using asp.net 1.1 and vb.net.When i try to run
both the applications in the same browsers, i get the following error.
(System.Security.Cryptography.CryptographicExcepti on: Bad Data. at
System.Security.Cryptography.CryptoAPITransform._D ecryptData(IntPtr
hKey, Byte[] rgb, Int32 ib, Int32 cb, Boolean fDone) at
System.Security.Cryptography.CryptoAPITransform.Tr ansformFinalBlock(Byte[]
inputBuffer, Int32 inputOffset, Int32 inputCount) at
System.Security.Cryptography.CryptoStream.FlushFin alBlock() at
System.Web.Configuration.MachineKey.EncryptOrDecry ptData(Boolean
fEncrypt, Byte[] buf, Byte[] modifier, Int32 start, Int32 length) at
System.Web.Security.FormsAuthentication.Decrypt(St ring
encryptedTicket))

That is, when i run the first application and run the second
application in the same browser, i get this error.If i run it in two
different browsers, then it works fine.

Can any one help me out.r u using Forms authentication?

"muthu" <s.muthumanickam@.gmail.comwrote in message
news:1152521970.538688.249490@.m73g2000cwd.googlegr oups.com...

Quote:

Originally Posted by

Hi,
>
I have two web applications running on my machine.The
application is developed using asp.net 1.1 and vb.net.When i try to run
both the applications in the same browsers, i get the following error.
(System.Security.Cryptography.CryptographicExcepti on: Bad Data. at
System.Security.Cryptography.CryptoAPITransform._D ecryptData(IntPtr
hKey, Byte[] rgb, Int32 ib, Int32 cb, Boolean fDone) at
System.Security.Cryptography.CryptoAPITransform.Tr ansformFinalBlock(Byte[]
inputBuffer, Int32 inputOffset, Int32 inputCount) at
System.Security.Cryptography.CryptoStream.FlushFin alBlock() at
System.Web.Configuration.MachineKey.EncryptOrDecry ptData(Boolean
fEncrypt, Byte[] buf, Byte[] modifier, Int32 start, Int32 length) at
System.Web.Security.FormsAuthentication.Decrypt(St ring
encryptedTicket))
>
That is, when i run the first application and run the second
application in the same browser, i get this error.If i run it in two
different browsers, then it works fine.
>
Can any one help me out.
>