Question

我在导航控制器中嵌入了一个控制器。假设我有一个按钮可以重新定位self.navigationController.navigationBar。然后我用任何控制器进行presentViewControllerAnimated（无论是否导航都没关系）并且在解除之后导航栏返回到它的原始位置（实际上它在解除动画开始时处于其原始位置）。在iOS 6及更早版本中，该栏不会自动重新定位。任何想法如何在iOS 7中阻止这种重新定位？

Answer 1

好的，所以我终于做对了。

首先 - Apple不希望我们改变UINavigationBar的位置。因此，您应该不惜一切代价避免它。在我的情况下，我有一个应用程序来修复它移动UINavigationBar显示滑出菜单。滑出菜单问题的正确解决方案是将UINavigationController 放在中 - 然后你可以用它的内容（无论它是什么）滑动整个UINavigationController，一切正常。出于某种原因，UINavigationController在这个应用程序之外。所以，我不得不诉诸黑客。如果您有任何选项不使用它，请不要使用此方法。这是一个黑客攻击，它可能会在更多的iOS版本中破解，Apple肯定不会欣赏它。

首先，探索iOS7中的新过渡系统：http://www.doubleencore.com/2013/09/ios-7-custom-transitions/

然后，替换：

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

带

if([UIApplication iOS7]) /* or any other custom iOS7 detection method you implement */
{ /* we simulate old transition with nav bar slided out */
  navigationController.transitioningDelegate = [OMModalTransitionDelegate new];
}

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

因此，我们需要一个转换委托来模拟标准行为并执行技巧。

#import "OMModalTransitionDelegate.h"
#import "OMAnimatedTransitioning.h"

@implementation OMModalTransitionDelegate

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
  OMAnimatedTransitioning *transitioning = [OMAnimatedTransitioning new];
  return transitioning;
}

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
  OMAnimatedTransitioning *transitioning = [OMAnimatedTransitioning new];
  transitioning.reverse = YES;
  return transitioning;
}

@end

现在是实际的动画管理器（你必须自己在UINavigationBar的类别中实现sharedBar）：

static NSTimeInterval const DEAnimatedTransitionDuration = 0.4f;
static NSTimeInterval const DEAnimatedTransitionMarcoDuration = 0.15f;


@implementation OMAnimatedTransitioning


- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
  UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
  UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
  UIView *container = [transitionContext containerView];
  UIView *superView = [UINavigationBar sharedBar].superview;
  CGRect barFrame = [UINavigationBar sharedBar].frame;
  if(self.reverse)
  { /* Trick - first, remove the bar from it's superview before animation starts */
    [[UINavigationBar sharedBar] removeFromSuperview];
  }
  CGRect oldFrame = container.bounds;
  if (self.reverse)
  {
    [container insertSubview:toViewController.view belowSubview:fromViewController.view];
  }
  else
  {
    toViewController.view.frame = oldFrame;
    toViewController.view.transform = CGAffineTransformMakeTranslation(0, CGRectGetHeight(oldFrame));
    [container addSubview:toViewController.view];
  }

[UIView animateKeyframesWithDuration:DEAnimatedTransitionDuration delay:0 options:0 animations:^
{
  if (self.reverse)
  {
    fromViewController.view.transform = CGAffineTransformMakeTranslation(0, CGRectGetHeight(oldFrame));
    double delayInSeconds = 0.01; /* Trick - after an imperceivable delay - add it back - now it is immune to whatever Apple put there to move it */
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void)
    {
        [UINavigationBar sharedBar].frame = barFrame;
        [superView addSubview:[UINavigationBar sharedBar]];
    });

  }
  else
  {
    toViewController.view.transform = CGAffineTransformIdentity;
  }
} completion:^(BOOL finished) {


  [transitionContext completeTransition:finished];
}];
}

- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext
{
  return DEAnimatedTransitionDuration;
}
@end

Answer 2

在自定义导航控制器中，添加

- (void)viewWillLayoutSubviews {
   //do your navigation bar layout
}

希望这可以帮到你。提醒一下，上面的方法只支持ios＆gt; = 5.0。

iOS 7 navigationBar在dismissViewController之后重新定位

2 个答案: