提交表格时未使用表达结果

Question

I know this has been asked before, but none of the answers have solved my problem. Here's the code I'm using to send a post request

NSString *nameField = _name.text;
NSString *emailField = _email.text;
NSString *usernameField = _username.text;
NSString *passwordField = _password.text;

NSURL *url = [NSURL URLWithString:@"http://localhost/api/register"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

NSData *requestData = [@"name=%@&email=%@&username=%@&password=%@",nameField, emailField, usernameField, passwordField dataUsingEncoding:NSUTF8StringEncoding];

[request setHTTPMethod:@"POST"];
[request setValue:@"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" forHTTPHeaderField:@"Accept"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setValue:[NSString stringWithFormat:@"%d", [requestData length]] forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody: requestData];

[[NSURLConnection alloc] initWithRequest:request delegate:self];

This line specifically gives me problems

NSData *requestData = [@"name=%@&email=%@&username=%@&password=%@",nameField, emailField, usernameField, passwordField dataUsingEncoding:NSUTF8StringEncoding];

The warning I get with it is

Expression result unused

Also I'd expect to get a result with my JSON so when there would be an error it would show it (backend part is done, it's just a matter of displaying it on iOS). I'm not even sure if it's submitting

Answer 1

You forgot to use +stringWithFormat: when defining requestData . Change that line to this:

NSData *requestData = [[NSString stringWithFormat:@"name=%@&email=%@&username=%@&password=%@", nameField, emailField, usernameField, passwordField] dataUsingEncoding:NSUTF8StringEncoding];

Also, you'll probably get the same warning on your last line. You can get rid of it by assigning it to something:

NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

You may also want to implement some of the NSURLConnection delegate methods. See this tutorial for some helpful info.