AFNetworking Post Request

I'm a newbie in obj-c and have been using asihttp for some of my projects. When doing a post request in asihttp its done this way.

    ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
    [request setPostValue:height forKey:@"user[height]"];
    [request setPostValue:weight forKey:@"user[weight]"];
    [request setDelegate:self];
    [request startAsynchronous];

How would go about doing this is AFNetworking with a code example ?
I already got the get Json getrequest working in AFNetworking but this post request is giving me some problems. Thanks for help in advance.

It's first worth adding (as this answer is still popular 6 years after I initially wrote it...) that the first thing you should consider is whether you should even use AFNetworking. NSURLSession was added in iOS 7 and means you don't need to use AFNetworking in many cases - and one less third party library is always a good thing.

For AFNetworking 3.0:

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
NSDictionary *params = @{@"user[height]": height,
                         @"user[weight]": weight};
[manager POST:@"https://example.com/myobject" parameters:params progress:nil success:^(NSURLSessionTask *task, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(NSURLSessionTask *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];

For AFNetworking 2.0 (and also using the new NSDictionary syntax):

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
NSDictionary *params = @{@"user[height]": height,
                         @"user[weight]": weight};
[manager POST:@"https://example.com/myobject" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];

If you are stuck using AFNetworking 1.0, you need to do it this way:

NSURL *url = [NSURL URLWithString:@"https://example.com/"];
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:url];

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                        height, @"user[height]",
                        weight, @"user[weight]",
                        nil];
[httpClient postPath:@"/myobject" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSString *responseStr = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
    NSLog(@"Request Successful, response '%@'", responseStr);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"[HTTPClient Error]: %@", error.localizedDescription);
}];

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                       height, @"user[height]",
                       weight, @"user[weight]",
                       nil];

AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:
                                             [NSURL URLWithString:@"http://localhost:8080/"]];

[client postPath:@"/mypage.php" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
     NSString *text = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
     NSLog(@"Response: %@", text);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
     NSLog(@"%@", [error localizedDescription]);
}];

Here is a simple AFNetworking POST I'm using. To get up and running after reading the AFNetworking doc, wkiki, ref, etc, I learned a lot by following http://nsscreencast.com/episodes/6-afnetworking and understanding the associated code sample on github.

 // Add this to the class you're working with - (id)init {}
    _netInst = [MyApiClient sharedAFNetworkInstance];

  // build the dictionary that AFNetworkng converts to a json object on the next line
  //  params = {"user":{"email":emailAddress,"password":password}};
  NSDictionary *parameters =[NSDictionary dictionaryWithObjectsAndKeys:
                             userName, @"email", password, @"password", nil];
  NSDictionary *params =[NSDictionary dictionaryWithObjectsAndKeys:
                         parameters, @"user", nil];

   [_netInst postPath: @"users/login.json" parameters:params
      success:^(AFHTTPRequestOperation *operation, id jsonResponse) {
        NSLog (@"SUCCESS");

        // jsonResponse = {"user":{"accessId":1234,"securityKey":"abc123"}};
        _accessId = [jsonResponse valueForKeyPath:@"user.accessid"];
        _securityKey = [jsonResponse valueForKeyPath:@"user.securitykey"];

        return SUCCESS;
      }
      failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"FAILED");

        // handle failure

        return error;
      }
   ];  

    AFHTTPClient * Client = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:@"http://urlname"]];
    NSDictionary * parameters = [[NSMutableDictionary alloc] init];
    parameters = [NSDictionary dictionaryWithObjectsAndKeys:
                 height, @"user[height]",
                        weight, @"user[weight]",
                  nil]; 

    [Client setParameterEncoding:AFJSONParameterEncoding];
    [Client postPath:@"users/login.json" parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"operation hasAcceptableStatusCode: %d", [operation.response statusCode]);

    NSLog(@"response string: %@ ", operation.responseString);

    NSDictionary *jsonResponseDict = [operation.responseString JSONValue];
        if ([[jsonResponseDict objectForKey:@"responseBody"] isKindOfClass:[NSMutableDictionary class]]) {
            NSMutableDictionary *responseBody =  [jsonResponseDict objectForKey:@"responseBody"];
           //get the response here


    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {

        NSLog(@"error: %@", operation.responseString);
        NSLog(@"%d",operation.response.statusCode);

    }];

Hope this works.

For AFNetworking 4

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
NSDictionary *params = @{@"user[height]": height,
                         @"user[weight]": weight};
[manager POST:@"https://example.com/myobject" parameters:params headers:nil progress:nil success:^(NSURLSessionTask *task, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(NSURLSessionTask *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];