Invalid web service call, missing value for parameter Objective C - ios

Question

From my iPhone app, I'm making a call to an ASP.NET web service. Below is my code
NSString *urlString = #"http://tbtesting/teambinder5/KEY9XXXXXX-cXXe-49XX2-acca-2XXXXXXXa9/Dashboard/DashboardWidgets.asmx/GetAnnouncement";
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
[request setValue:#"*/*" forHTTPHeaderField:#"Accept"];
[request setValue:#"application/json; charset=utf-8" forHTTPHeaderField:#"Content-Type"];
[request setValue:#"en-us" forHTTPHeaderField:#"Accept-Language"];
[request setValue:#"gzip, deflate" forHTTPHeaderField:#"Accept-Encoding"];
[request setValue:#"20" forHTTPHeaderField:#"Content-Length"];
//[request setValue:#"3" forHTTPHeaderField:#"announceIntKey"];
NSError *error = nil;
NSURLResponse *response = [[NSURLResponse alloc] init];
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if (error) {
NSLog(#"Following error occured: %#", error.localizedDescription);
}
else {
NSString *returnValue = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"message: %#", returnValue);
}
Here is the header taken from fiddler.
POST http://tbtesting/teambinder5/KEY9XXXXXX-cXXe-49XX2-acca-2XXXXXXXa9/Dashboard/DashboardWidgets.asmx/GetAnnouncement HTTP/1.1
Accept: */*
Accept-Language: en-us
Content-Type: application/json; charset=utf-8
Accept-Encoding: gzip, deflate
Content-Length: 20
{"announceIntKey":3}
I'm getting the following error message.
"Message":"Invalid web service call, missing value for parameter: \u0027announceIntKey\u0027."
After a little bit of searching here on SO I found out the cause for this error. It is because I'm not passing the announceIntKey and its value.
Although I know the reason, I'm kinda clueless on how to correct it. Since it looks like an object literal, you can't pass it like any other header value. All the example code I came across here on SO is for jQuery or some other language.
My question is how can I pass this value in Objective C?
Thank you.

Answer 1

It looks like you're sending the content-type of application/json, so it would stand to reason that you need to pass the value as part of a POST containing a JSON body.
You will need to add that to the body of your request. You don't need to set the content-length as the NSMutableURLRequest will manage this for you.
NSString *body = "{\"announceIntKey\" : VALUE}";
[request setHTTPBody:[body dataUsingEncoding:NSASCIIStringEncoding]];
You'll need to replace VALUE with what actually goes into the announceIntKey.