Jpeg displaying as base64 string in browser

[Magnus]

Hi,
I'm programatically posting an image using multipart/form-data. It sends to the server OK, but when I try to view it in the browser, it is still in the base64 string I sent it as: /9j/4AAQSkZJRgABAQA AAQABAAD/2wBDAAUDBAQEAwU EBAQFBQUG etc....

I've been through the form I built over and over:

string PostData = "";

PostData += "-----------------------------7d41fb3081216";
PostData += "\r";
PostData += "\n";

PostData += "Content-Disposition: form-data; name=\"userfile \"; filename=" + "\"c:\\temp \\" + "myimg.jpg\ ";";
PostData += "\r";
PostData += "\n";

PostData += "Content-Type: image/jpeg; name=\"myimg.jp g\";";
PostData += "\r";
PostData += "\n";

PostData +="Content-Transfer-Encoding: binary;";
PostData += "\r";
PostData += "\n";
PostData += "\r";
PostData += "\n";

string image_string = Convert.ToBase6 4String(documen tcontents);
PostData += image_string;

PostData += "\r";
PostData += "\n";

PostData += "-----------------------------7d41fb3081216--";

This is the how i'm reading the image in:

string strdocPath;
strdocPath = "c:\\temp\\ " + "myimg.jpg" ;

FileStream objfilestream = new FileStream(strd ocPath,FileMode .Open,FileAcces s.Read);
int len = (int)objfilestr eam.Length;
Byte[] documentcontent s = new Byte[len];
objfilestream.R ead(documentcon tents,0,len);
objfilestream.C lose();
I've tried pretty much every order of mimes, but still the image isn't sent properly. Does anyone have any experience of this or what could be causing the base64 string to show like that?

Thanks

[Jon Skeet [C# MVP]]

Magnus <Ma****@discuss ions.microsoft. com> wrote:

I'm programatically posting an image using multipart/form-data. It
sends to the server OK, but when I try to view it in the browser, it
is still in the base64 string I sent it as:
/9j/4AAQSkZJRgABAQA AAQABAAD/2wBDAAUDBAQEAwU EBAQFBQUG etc....

I've been through the form I built over and over:

string PostData = "";

PostData += "-----------------------------7d41fb3081216";
PostData += "\r";
PostData += "\n";
You should really be using a StringBuilder for this - you're creating
laods of extra strings.
PostData += "Content-Disposition: form-data; name=\"userfile \"; filename=" + "\"c:\\temp \\" + "myimg.jpg\ ";";
PostData += "\r";
PostData += "\n";

PostData += "Content-Type: image/jpeg; name=\"myimg.jp g\";";
PostData += "\r";
PostData += "\n";

PostData +="Content-Transfer-Encoding: binary;";
What have you specified binary for the Content-Transfer-Encoding when
you're actually using Base64? I suspect that's the problem.
PostData += "\r";
PostData += "\n";
PostData += "\r";
PostData += "\n";

string image_string = Convert.ToBase6 4String(documen tcontents);
PostData += image_string;

PostData += "\r";
PostData += "\n";

PostData += "-----------------------------7d41fb3081216--";

This is the how i'm reading the image in:

string strdocPath;
strdocPath = "c:\\temp\\ " + "myimg.jpg" ;

FileStream objfilestream = new FileStream(strd ocPath,FileMode .Open,FileAcces s.Read);
int len = (int)objfilestr eam.Length;
Byte[] documentcontent s = new Byte[len];
objfilestream.R ead(documentcon tents,0,len);
objfilestream.C lose();

That's an unsafe way of reading a file, as well: you're not closing the
file if there's an exception, and you're assuming that Read will return
all the data.

See http://www.pobox.com/~skeet/csharp/readbinary.html for more info.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Magnus]

Jon Thanks, I'm using your ReadFully function now. In addition I was making two mistakes:
I was using the GetBytes method instead of Encoding.Defaul t.GetString to convert my file buffer,
and secondly I was posting the ContentLength of PostData, rather than theContentLengt h of a Byte array that is converted with GetBytes. It works now.

"Jon Skeet [C# MVP]" wrote:

Magnus <Ma****@discuss ions.microsoft. com> wrote:

I'm programatically posting an image using multipart/form-data. It
sends to the server OK, but when I try to view it in the browser, it
is still in the base64 string I sent it as:
/9j/4AAQSkZJRgABAQA AAQABAAD/2wBDAAUDBAQEAwU EBAQFBQUG etc....

I've been through the form I built over and over:

string PostData = "";

PostData += "-----------------------------7d41fb3081216";
PostData += "\r";
PostData += "\n";

You should really be using a StringBuilder for this - you're creating
laods of extra strings.

PostData += "Content-Disposition: form-data; name=\"userfile \"; filename=" + "\"c:\\temp \\" + "myimg.jpg\ ";";
PostData += "\r";
PostData += "\n";

PostData += "Content-Type: image/jpeg; name=\"myimg.jp g\";";
PostData += "\r";
PostData += "\n";

PostData +="Content-Transfer-Encoding: binary;";

What have you specified binary for the Content-Transfer-Encoding when
you're actually using Base64? I suspect that's the problem.

PostData += "\r";
PostData += "\n";
PostData += "\r";
PostData += "\n";

string image_string = Convert.ToBase6 4String(documen tcontents);
PostData += image_string;

PostData += "\r";
PostData += "\n";

PostData += "-----------------------------7d41fb3081216--";

This is the how i'm reading the image in:

string strdocPath;
strdocPath = "c:\\temp\\ " + "myimg.jpg" ;

FileStream objfilestream = new FileStream(strd ocPath,FileMode .Open,FileAcces s.Read);
int len = (int)objfilestr eam.Length;
Byte[] documentcontent s = new Byte[len];
objfilestream.R ead(documentcon tents,0,len);
objfilestream.C lose();

That's an unsafe way of reading a file, as well: you're not closing the
file if there's an exception, and you're assuming that Read will return
all the data.

See http://www.pobox.com/~skeet/csharp/readbinary.html for more info.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Jon Skeet [C# MVP]]

Magnus <Ma****@discuss ions.microsoft. com> wrote:

Jon Thanks, I'm using your ReadFully function now. In addition I was
making two mistakes: I was using the GetBytes method instead of
Encoding.Defaul t.GetString to convert my file buffer
Where are you converting the file buffer?
and secondly I
was posting the ContentLength of PostData, rather than
theContentLengt h of a Byte array that is converted with GetBytes. It
works now.

Good - but I'm still slightly worried about using Encoding.Defaul t
anywhere...

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Magnus]

I admit that it's more by trial and error, than knowledge that I got it working:

byte [] b = ReadFully(str,( int)str.Length) ;

string image_data=Enco ding.Default.Ge tString(b); //here's what I mean by converting.
str.Close();

PostData += image_data;

//other form info etc..
//..

//write it out

Byte [] Buffer = Encoding.Defaul t.GetBytes(Post Data);
Request.Content Length=Buffer.L ength;

Stream newStream = Request.GetRequ estStream();

newStream.Write (Buffer, 0, Buffer.Length);
newStream.Flush ();
newStream.Close ();

//get response stream ..

"Jon Skeet [C# MVP]" wrote:

Magnus <Ma****@discuss ions.microsoft. com> wrote:

Jon Thanks, I'm using your ReadFully function now. In addition I was
making two mistakes: I was using the GetBytes method instead of
Encoding.Defaul t.GetString to convert my file buffer

Where are you converting the file buffer?

and secondly I
was posting the ContentLength of PostData, rather than
theContentLengt h of a Byte array that is converted with GetBytes. It
works now.

Good - but I'm still slightly worried about using Encoding.Defaul t
anywhere...

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Jon Skeet [C# MVP]]

Magnus <Ma****@discuss ions.microsoft. com> wrote:

I admit that it's more by trial and error, than knowledge that I got it working:

byte [] b = ReadFully(str,( int)str.Length) ;

string image_data=Enco ding.Default.Ge tString(b); //here's what I mean by converting.
str.Close();

PostData += image_data;

//other form info etc..
//..

//write it out

Byte [] Buffer = Encoding.Defaul t.GetBytes(Post Data);
Request.Content Length=Buffer.L ength;

Stream newStream = Request.GetRequ estStream();

newStream.Write (Buffer, 0, Buffer.Length);
newStream.Flush ();
newStream.Close ();

//get response stream ..

Ah. That's bad news. What you should do instead is avoid *ever*
encoding or decoding the binary data. Write the text using
Encoding.ASCII. GetBytes (...) to get the byte array for each part, and
then just write the image data directly.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too