oc调用rest api

无需其他类库

- (IBAction)callapi:(id)sender {
    NSURL *url=[NSURL URLWithString:@"http://..."];
    NSURLRequest *request=[NSURLRequest requestWithURL:url];
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        //json
        NSDictionary *r=[NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
        int cnt=[r count];
        NSLog(@"%d",cnt);
        [self resultlbl].text=[NSString stringWithFormat:@"%d",cnt];

        //string
        //NSString *str=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        //NSLog(str);
        //[self resultlbl].text=r[0][0];
    }];
}

post

- (IBAction)postsend:(id)sender {
    NSURL *url = [NSURL URLWithString:@"http://...."];
    NSMutableURLRequest *rq = [NSMutableURLRequest requestWithURL:url];
    [rq setHTTPMethod:@"POST"];

    NSData *jsonData = [@"{ "参数名": 数值,"参数名":"字符"... }" dataUsingEncoding:NSUTF8StringEncoding];
    [rq setHTTPBody:jsonData];

    [rq setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [rq setValue:[NSString stringWithFormat:@"%ld", (long)[jsonData length]] forHTTPHeaderField:@"Content-Length"];

    [NSURLConnection sendAsynchronousRequest:rq queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        //code
        NSString *str=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        NSLog(str);
    }];

}