Ios 切换视图（视图控制器）

我使用iAction来切换视图，而不必先通过dismissing进入根目录。这两个代码工作正常，但我想知道的区别和什么将是最好的一个用于内存控制可能！？！区别在第二行…[自我…]

-(IBAction)switchpage13:(id)sender
{
    UIViewController *parentViewController = self.presentingViewController;
    [self dismissViewControllerAnimated:NO completion:^
     {
    BalladViewController *ballad = [[BalladViewController alloc]
                                      initWithNibName:@"BalladViewController_iPad" bundle:nil];

         [parentViewController presentViewController:ballad  animated:NO completion:nil];
         [ballad release];
     }];
}

或

---

没有区别。从DismissViewControllerInitiated:completion:-如果您在演示视图控制器本身上调用此方法，它会自动将消息转发给演示视图控制器……。感谢rdelmar。

-(IBAction)switchpage14:(id)sender{
    UIViewController *parentViewController = self.presentingViewController;
    [self.presentingViewController dismissViewControllerAnimated:NO completion:^
     {
         PopViewController *pop = [[PopViewController alloc]
                                           initWithNibName:@"PopViewController_iPad" bundle:nil];

         [parentViewController presentViewController:pop  animated:NO completion:nil];
         [pop release];
     }];
}