Get Variable from httpcontext coming from NSUrlRequest - connection

Question

This question will be a nice tutorial for http connection "POST" between Iphone and asp.net server :) what i'm trying to do is to send an image from iphone to Asp.net server;
Here my uploadImage fonction in objective-c :
- (IBAction)uploadImage {
/*
turning the image into a NSData object
getting the image back out of the UIImageView
setting the quality to 90
*/
NSData *imageData = UIImageJPEGRepresentation(image.image, 33);
// setting up the URL to post to
NSString *urlString = #"MyWebServiceUrl";
// setting up the request object now
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:#"POST"];
/*
add some header info now
we always need a boundary when we post a file
also we need to set the content type
You might want to generate a random boundary.. this is just the same
as my output from wireshark on a valid html post
*/
NSString *boundary = [NSString stringWithString:#"---------------------------14737809831466499882746641449"];
NSString *contentType = [NSString stringWithFormat:#"multipart/form-data; boundary=%#",boundary];
[request addValue:contentType forHTTPHeaderField: #"Content-Type"];
/*
now lets create the body of the post
*/
NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"Content-Disposition: form-data; filepath=\"ProfilePic\"; filename=\"ipodfile\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:imageData]];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
// setting the body of the post to the reqeust
[request setHTTPBody:body];
// now lets make the connection to the web
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
NSLog(#"%#", returnString);
}
And here is my webService Fonctions that parse the data sent and save the file :
public class SaveData : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
bool hasErrors = false;
HttpFileCollection filesPosted = context.Request.Files;
String filePath = context.Request.QueryString["filepath"];
String fileName = context.Request.QueryString["filename"];
try
{
if (String.IsNullOrEmpty(fileName) || String.IsNullOrEmpty(filePath) || filesPosted.Count <= 0)
hasErrors = true;
if (!hasErrors)
{
HttpContext.Current.Response.Write(WriteFile(filesPosted[0], filePath, fileName));
}
else
{
context.Response.Write("Failed: parsing error");
}
}
catch (Exception ex)
{
context.Response.Write("Failed: exception error:::" + ex.Message);
}
}
private string WriteFile(HttpPostedFile file, String filePath, String fileName)
{
System.IO.Directory.CreateDirectory(filePath);
int counter = 0;
string path = String.Format("{0}\\{1}.jpg", filePath, fileName);
while (System.IO.File.Exists(path))
{
counter++;
path = String.Format("{0}\\{1}-{2}.jpg", filePath, fileName, counter);
}
file.SaveAs(path);
return path;
}
public bool IsReusable
{
get
{
return false;
}
}
}
my problem come from this two lines
String filePath = context.Request.QueryString["filepath"];
String fileName = context.Request.QueryString["filename"];
context.Request.QueryString is returning null so my hasErrors is false; any ideas how to fix that will be so appreciated, thanks for all.

Answer 1

The query string gets populated from the Url parameters (http://someserver.com/foobar?field1=value1&field2=value2)
To access form data sent in the POST body, use either Request.Form["filepath"] or the shorthand Request["filepath"], which looks for the item in the Form, QueryString, Cookies and ServerVariables collection.
Data of posted files can be found in Request.Files

Answer 2

here the solution after a day of trying:
client code:
// post body
NSMutableData *body = [NSMutableData data];
// add params (all params are strings)
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"%#\"\r\n\r\n", #"filename"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"%#\r\n", imageName] dataUsingEncoding:NSUTF8StringEncoding]];
// add image data
if (imageData) {
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"myImage\"; filename=\"image.jpg\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:imageData];
[body appendData:[[NSString stringWithFormat:#"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
}
Asp.net Server code:
String filePath = context.Request.Form["filename"];
hope you like this question(tutorial) ;)