XCode will not recognize custom method

I have a custom NSObject class called "GREST", everything works aside from this method. Auto completion won't even recognize it, and I honestly can't figure out why. I've tried changing the method's name and everything. When I call the method, it works, I just get the warning that the class may not respond to this method.

I have this method declared in my header file

- (void)connect:(NSString *)connection_url parameters:(NSString *)parameter_string header:(NSString *)header_type

And here is the implementation

- (void)connect:(NSString *)connection_url parameters:(NSString *)parameter_string header:(NSString *)header_type {

    NSData *request_data = [parameter_string dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
    NSString *request_length = [NSString stringWithFormat:@"%d", [request_data length]];

    response_data = [[NSMutableData alloc] init];

    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
    [request setURL:[NSURL URLWithString:connection_url]];
    [request setHTTPMethod:@"POST"];
    [request setValue:request_length forHTTPHeaderField:@"Content-Length"];
    if([header_type isEqualToString:@""] || header_type == nil || header_type == NULL) {
        [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    } else {
        [request setValue:header_type forHTTPHeaderField:@"Content-Type"];
    }
    [request setHTTPBody:request_data];
    [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
    [request setTimeoutInterval:10];

    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];
    if(!connection) {
        [self apicall_failed];
    }
    [connection release];

}

When I try to call this method, XCode gi开发者_如何学运维ves me the following warning

'GREST' may not respond to '-connect:parameter_string:header_type:'

Edit, here's how the code is being called:

GREST *api = [[GREST alloc] init];
[api setDelegate:self];
[api connect:@"http://domain.com" parameter_string:@"{'username':'hi'}" header_type:@"application/json"];
[api release];

Everything works fine, but I'm just trying to get rid of this warning now. Any ideas on how I can do this? Thanks in advance!

compare the method names:

'-connect:parameter_string:header_type:'

to

'-connect:parameters:header:'

the difference is that you are using the names of the method's arguments, not the actual method/selector. this will result in a runtime exception when called.

the compiler will tell you the line where you try to use the former, and xcode will probably highlight the line.

Change

[api connect:@"http://domain.com" parameter_string:@"{'username':'hi'}" header_type:@"application/json"];

to

[api connect:@"http://domain.com" parameters:@"{'username':'hi'}" header:@"application/json"];