NSURL *url = [NSURL URLWithString:@"https://www.baidu.com"];    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];    request.HTTPMethod = @"POST"; 　　// 请求参数    NSString *bodyStr = [NSString stringWithFormat:@"username=%@&password=%@", username, password];    request.HTTPBody = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];    NSData *data =[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

NSError *error = nil;    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];    NSLog(@"---------------%@", json);