- (IBAction)loginAction:(id)sender {
    
    UIStoryboard *main=[UIStoryboard storyboardWithName:@"Main" bundle:nil];//storyboard标示
    
    RegisterViewController *vc=[main instantiateViewControllerWithIdentifier:@"RegisterConroller"];//控制器标示
    [self.navigationController pushViewController:vc animated:YES];
    

}