NSString *qq=[NSString stringWithFormat:@"mqq://im/chat?chat_type=wpa&uin=%@&version=1&src_type=web",@""];

    NSURL *url2 = [NSURL URLWithString:qq];

    if ([[UIApplication sharedApplication] canOpenURL:url2]) {

        [[UIApplication sharedApplication] openURL:url2];

    }else{

        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示" message:@"对不起，您还没安装QQ" preferredStyle:UIAlertControllerStyleAlert];

        UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {

            return ;

        }];

        [alertController addAction:cancelAction];

        [self presentViewController:alertController animated:YES completion:nil];

    }