I want to make a POST to a PHP site from a C# WinForm Application in a Browser window (or a WebBrowser-instance) with .net 2.0 and I need to get the data and the headers-argments right. Like:
webBrowser1.Navigate("http://mypublishservice.com/publish_picture.php","_SELF",X,Y);
The question is: What should be X and Y? I know a have to fill all headers and file data in a byte[] array and add some additional headers as strings. I made examples of the webform below and examined them with firebug. So i know how the POST data should look like. I even created a HttpWebRequest which was ok, but I need a WebBrowser (reasons below) to start the Post-Request. So i am lost. I have tried many options, e.g. Upload files with HTTPWebrequest (multipart/form-data). Maybe there is a better way, by creating a HttpWebrequest and than passing this to a WebBrowser-instance or something like that?
Here is a web form to call the publish_picture.php page that works fine:
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<div>
<form enctype="multipart/form-data" action="http://mypublishservice.com/publish_picture.php" method="POST">
Please choose a photo:
<input name="source" type="file"><br/><br/>
Say something about this photo:
<input name="message" type="text" value=""><br/><br/>
<input type="submit" value="Upload"/><br/>
</form>
</div>
</body>
</html>
In case you ask why I want to do it THIS way, here some thoughts to defend my silly decision 😉
Why a WebBrowser-instance and not a simple HttpWebrequest? Because the target service (e.g. Facebook) needs (or seems to need) a proper Browser!
Why not the target service APIs (e.g. Facebook API)? Found out, that Desktop-Web-communication is not good (too many 400-Errors).
UPDATE 2:
Looks better. Still I get an error but it might be the PHP page itself. Is this what you have in mind?
public static byte[] PrepareUploadFiles(string address, IEnumerable<UploadFile> files, NameValueCollection values, out string header)
{
using (var requestStream = new MemoryStream())
{
var boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); //, NumberFormatInfo.InvariantInfo);
header = "multipart/form-data; boundary=" + boundary;
var boundaryBuffer2 = Encoding.ASCII.GetBytes(header);
requestStream.Write(boundaryBuffer2, 0, boundaryBuffer2.Length);
boundary = "--" + boundary;
// Write the values
foreach (string name in values.Keys)
{
var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"{1}{1}", name, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes(values[name] + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
}
// Write the files
foreach (var file in files)
{
var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.UTF8.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"{2}", file.Name, file.Filename, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
buffer = Encoding.ASCII.GetBytes(string.Format("Content-Type: {0}{1}{1}", file.ContentType, Environment.NewLine));
requestStream.Write(buffer, 0, buffer.Length);
CopyStream(file.Stream, requestStream); // file.Stream.CopyTo(requestStream);
buffer = Encoding.ASCII.GetBytes(Environment.NewLine);
requestStream.Write(buffer, 0, buffer.Length);
}
var boundaryBuffer = Encoding.ASCII.GetBytes(boundary + "--");
requestStream.Write(boundaryBuffer, 0, boundaryBuffer.Length);
return requestStream.ToArray();
}
}
public static void CopyStream(Stream input, Stream output)
{
byte[] buffer = new byte[32768];
while (true)
{
int read = input.Read(buffer, 0, buffer.Length);
if (read <= 0)
return;
output.Write(buffer, 0, read);
}
}
public void Upload()
{
using (var stream1 = File.Open(Support.EXAMPLEIMAGE, FileMode.Open))
{
var files = new[]
{
new UploadFile
{
Name = "source", // 1
Filename = Support.EXAMPLEIMAGE,
ContentType = "image/jpeg", // 2
Stream = stream1
}
};
var values = new NameValueCollection
{
{ "message", "a text" } // 3
};
string contentType; // 4. do I need it
byte[] dataToPost = Support.PrepareUploadFiles(Support.URL, files, values, out contentType); // 5. out contentType = what should be the result vaule?
//PrepareUploadFiles(url, files, values, out contentType);
webBrowser1.Navigate(Support.URL, null, dataToPost, "Content-Type: " + contentType + Environment.NewLine);
}
}
Personally I like using the ParseQueryString method as it takes care of properly encoding parameters:
Now, because you are trying to upload files this is going to be a little more difficult. I wrote a blog post which illustrates how to generate a
multipart/form-datarequest allowing to upload multiple files. So you could tweak the UploadFiles method shown there to only return the POST body and not do the actual upload and then: