返回到navigationcontroller的根視圖然後push一個

        //跳到登錄界面

        for (int i = 0; i < self.navigationController.viewControllers.count; i++) {

            if ([[self.navigationController.viewControllers objectAtIndex:i] class] == [LoadingViewController class]) {

                LoadingViewController *vcLoading = [self.navigationController.viewControllers objectAtIndex:i];

                [vcLoading onLogin:nil]; / [vcLoading gotoLoginAfter1Seconds];

                [self.navigationController popToViewController:vcLoading animated:YES];

                break;

            }

        }

- (IBAction)onLogin:(id)sender {

    LoginViewController *vcLogin = [[LoginViewController alloc] initWithNibName:@"LoginViewController" bundle:nil];

    [self.navigationController pushViewController:vcLogin animated:YES];

    [vcLogin release];

}

- (void)gotoLoginAfter1Seconds {

    [self performSelector:@selector(onLogin:) withObject:nil afterDelay:0.51];

}

1，將animated都設置爲NO可以

2，設置一定的延遲時間

3，用委託方法

4，判斷是否已經完全pop，否則不執行push