复制iOS Mail App的Compose Function的样式

Question

我正在iOS 8上构建一个应用程序,我希望在创建新的电子邮件/消息时复制iOS的邮件应用程序的功能.如下所示:compose视图控制器显示在收件箱视图控制器的顶部,但是compose vc不占用整个屏幕.有没有比使用视图控制器的框架进行黑客攻击更容易的方法？谢谢!

Answer 1

这个效果可以UIPresentationController在iOS 8中实现.苹果有关于这个主题的WWDC '14视频以及在这篇文章底部找到的一些有用的示例代码(我在这里发布的原始链接不再有效).

*该演示称为"LookInside:演示控制器适应性和自定义动画对象".Apple的代码中存在一些与过时的API使用相对应的错误,可以通过将损坏的方法名称(在多个位置)更改为以下内容来解决:

initWithPresentedViewController:presentingViewController:

以下是您可以在iOS 8邮件应用程序上复制动画的操作.为了达到预期的效果,下载我上面提到的项目,然后你要做的就是改变一些事情.

首先,转到AAPLOverlayPresentationController.m并确保已实现该frameOfPresentedViewInContainerView方法.我看起来像这样:

- (CGRect)frameOfPresentedViewInContainerView
{
    CGRect containerBounds = [[self containerView] bounds];
    CGRect presentedViewFrame = CGRectZero;
    presentedViewFrame.size = CGSizeMake(containerBounds.size.width, containerBounds.size.height-40.0f);
    presentedViewFrame.origin = CGPointMake(0.0f, 40.0f);
    return presentedViewFrame;
}

关键是你希望presentViewController的框架从屏幕顶部偏移,这样你就可以实现一个视图控制器与另一个视图控制器重叠的外观(没有模态完全覆盖presentViewController).

接下来,animateTransition:在AAPLOverlayTransitioner.m中找到该方法,并将代码替换为下面的代码.您可能希望根据自己的代码调整一些内容,但总体而言,这似乎是解决方案:

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIView *fromView = [fromVC view];
    UIViewController *toVC   = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIView *toView = [toVC view];

    UIView *containerView = [transitionContext containerView];

    BOOL isPresentation = [self isPresentation];

    if(isPresentation)
    {
        [containerView addSubview:toView];
    }

    UIViewController *bottomVC = isPresentation? fromVC : toVC;
    UIView *bottomPresentingView = [bottomVC view];

    UIViewController *topVC = isPresentation? toVC : fromVC;
    UIView *topPresentedView = [topVC view];
    CGRect topPresentedFrame = [transitionContext finalFrameForViewController:topVC];
    CGRect topDismissedFrame = topPresentedFrame;
    topDismissedFrame.origin.y += topDismissedFrame.size.height;
    CGRect topInitialFrame = isPresentation ? topDismissedFrame : topPresentedFrame;
    CGRect topFinalFrame = isPresentation ? topPresentedFrame : topDismissedFrame;
    [topPresentedView setFrame:topInitialFrame];

    [UIView animateWithDuration:[self transitionDuration:transitionContext]
                          delay:0
         usingSpringWithDamping:300.0
          initialSpringVelocity:5.0
                        options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState
                     animations:^{
                         [topPresentedView setFrame:topFinalFrame];
                         CGFloat scalingFactor = [self isPresentation] ? 0.92f : 1.0f;
                         //this is the magic right here
                         bottomPresentingView.transform = CGAffineTransformScale(CGAffineTransformIdentity, scalingFactor, scalingFactor);

                    }
                     completion:^(BOOL finished){
                         if(![self isPresentation])
                         {
                             [fromView removeFromSuperview];
                         }
                        [transitionContext completeTransition:YES];
                    }];
}

目前,我还没有针对iOS 8之前的操作系统版本提供解决方案,但如果您想出一个,请随时添加答案.谢谢.

更新:

似乎上面的链接不再有效.可在此处找到相同的项目:https://developer.apple.com/library/ios/samplecode/LookInside/LookInsidePresentationControllersAdaptivityandCustomAnimatorObjects.zip

Answer 2

更新 - 2018年6月:

@ChristopherSwasey更新了repo以与Swift 4兼容.感谢Christopher!

对于未来的旅行者来说,Brian的帖子非常棒,但是有很多关于UIPresentationController(它促进了这个动画)的很好的信息我强烈建议你研究一下.我创建了一个包含iOS Mail应用程序组合动画的Swift 1.2版本的repo.我还在ReadMe中提供了大量相关资源.请在此处查看:https:
//github.com/kbpontius/iOSComposeAnimation