这是第一次遇到响应纯文本格式的，昨天遇到的，今天把这段代码写下来，分享给大家。
NSURL *url = [NSURL URLWithString:@"http://www.yuyigufen.com/index.php/Register/checkPCode"];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

request.HTTPMethod = @"POST";
request.HTTPBody = [@"mobile=17078075655&code=" dataUsingEncoding:NSUTF8StringEncoding];

[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
    
    NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    
    NSLog(@"判断验证码:%@",string);
    
}];