我本來試用方法：

- (IBAction)dismiss:(id)sender {
    if ([self respondsToSelector:@selector(dismissViewControllerAnimated:completion:)]) {
        //判斷1
        [self dismissViewControllerAnimated:YES completion:nil];
    } else if ([self.navigationController respondsToSelector:@selector(popViewControllerAnimated:)]) {
        //判斷2
        [self.navigationController popViewControllerAnimated:YES];
    }
}

結(jié)果發(fā)現(xiàn)不管是push或present，都只進判斷1，不進判斷2.
于是google，

方法一：

通過判斷self有沒有present方式顯示的父視圖presentingViewController

- (IBAction)dismiss:(id)sender {
    if (self.presentingViewController) {
        [self dismissViewControllerAnimated:YES completion:nil];
    } else {
        [self.navigationController popViewControllerAnimated:YES];
    }
}

方法二：

通過判斷self.navigationController.viewControllers的最后一個是否是當前控制器，或者self.navigationController.topViewController == self

- (IBAction)dismiss:(id)sender {
    if (self.navigationController.topViewController == self) {
        [self.navigationController popViewControllerAnimated:YES];
    } else {
        [self dismissViewControllerAnimated:YES completion:nil];
    }
}