当iOS8上的键盘出现时,移动模态呈现的UIViewController

Question

我在UINavigationController中有一个UIViewController,在带有iOS8的iPad上进行模态显示.我正在使用

self.myNavController.modalPresentationStyle = UIModalPresentationFormSheet;

在我的视图控制器中,我有一个文本字段.由于视图控制器的UI设计,当用户点击文本字段并出现键盘时,我需要在屏幕上向上移动视图控制器.在iOS7上,我一直在动画改变

self.myNavController.view.superview.frame.origin

为了向上移动视图控制器,然后向下移动.这很好用.

但是,在iOS8上,这已不再适用.实际上,奇怪的是,行为是视图控制器稍微向下移动然后再向上移动(所有当我分配self.myNavController.view.superview.frame.origin具有较小值Y坐标的CGPoint时).

最初,我正在根据这个SO问题给出的建议调整Resize ModalViewController并将其定位在iOS 7的中心位置

我最近尝试了当键盘存在工作时移动对话框中给出的建议, 除非当ipad转向但没有用.实际上,随着转换思想的回答,我至少可以让视图控制器向正确的方向移动(即向上),但它不会停留在那里.它很快就会回落.

想法？

Answer 1

我们会的，我现在很兴奋。我已经弄清楚了。这可以使用新的 iOS8 UIPresentationController 来解决。我将在下面给出一些示例代码。稍后尝试链接到工作项目 zip 文件。

第一个视图控制器是示例应用程序的根视图控制器。ChangeFrameTransitioningDelegate 的代码如下。“Dialog”只是一个空的视图控制器类。

//
//  ViewController.m
//  TestPresentationController
//
//  Created by Christopher Prince on 9/21/14.
//  Copyright (c) 2014 Spastic Muffin, LLC. Use at your own discretion.
//

#import "ViewController.h"
#import "ChangeFrameTransitioningDelegate.h"
#import "Dialog.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void) viewDidAppear:(BOOL)animated;
{
    [super viewDidAppear:animated];

    ChangeFrameTransitioningDelegate *td = [ChangeFrameTransitioningDelegate new];
    td.viewControllerFrame = CGRectMake(100, 0, 100, 100);

    Dialog *d = [Dialog new];
    // Just to make the VC stand out.
    d.view.backgroundColor = [UIColor greenColor];

    // Need to make this custom in order to have the presentationControllerForPresentedViewController method of the transitioning delegate called.
    d.modalPresentationStyle = UIModalPresentationCustom;

    d.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
    d.transitioningDelegate = td;

    [self presentViewController:d animated:YES completion:^{

        // Any time after the view controller is presented you can change the
        // viewControllerFrame property to change the size and/or position of the 
        // presented view controller.
        [UIView animateWithDuration:0.5 animations:^{
            td.viewControllerFrame = CGRectMake(100, 800, 100, 100);
        }];
    }];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

//
//  ChangeFrameTransitioningDelegate.h
//  TestPresentationController
//
//  Created by Christopher Prince on 9/21/14.
//  Copyright (c) 2014 Spastic Muffin, LLC. Use at your own discretion.
//

// For iOS8 and later, use this to change the size/position of a view controller after it has been presented. See TextPresentationController example.
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface ChangeFrameTransitioningDelegate : NSObject<UIViewControllerTransitioningDelegate>

// This is the size and position that the PresentationController used by this class will use when its frameOfPresentedViewInContainerView method is called. So, this is the size and position that your view controller will have.
@property (nonatomic) CGRect viewControllerFrame;

@end

//
//  ChangeFrameTransitioningDelegate.m
//  TestPresentationController
//
//  Created by Christopher Prince on 9/21/14.
//  Copyright (c) 2014 Spastic Muffin, LLC. Use at your own discretion.
//

// Some help from http://stackoverflow.com/questions/25903412/editing-bounds-of-uiview-when-presenting-hides-keyboard-in-ios-8
// http://stackoverflow.com/questions/25811199/ios-8-change-the-size-of-presented-modal-view-controller
// Some code from https://developer.apple.com/devcenter/download.action?path=/wwdc_2014/wwdc_2014_sample_code/lookinsidepresentationcontrollersadaptivityandcustomanimatorobjects.zip (though, beware, this example doesn't work straight out of the box).
// And see http://stackoverflow.com/questions/25957343/moving-a-modally-presented-uiviewcontroller-up-when-keyboard-appears-on-ipad-wit

#ifndef SPASLogDetail
#define SPASLogDetail NSLog
#endif

#import "ChangeFrameTransitioningDelegate.h"

@interface PresentationController : UIPresentationController
{
    UIView *_dimmingView;
}
// This is the size and position that the PresentationController will use when its frameOfPresentedViewInContainerView method is called.
@property (nonatomic) CGRect currentFrame;
@end

@implementation PresentationController

- (instancetype)initWithPresentedViewController:(UIViewController *)presentedViewController presentingViewController:(UIViewController *)presentingViewController;
{
    self = [super initWithPresentedViewController:presentedViewController presentingViewController:presentingViewController];
    // Some random default size.
    self.currentFrame = CGRectMake(0, 0, 100, 100);
    [self prepareDimmingView];
    return self;
}

// 4/22/15; Added, for rotation.
- (void) viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator;
{
    CGSize increasedSize = size;
    // 4/22/15; I'm getting some odd effects: In a rotation transition from landscape to portrait, the RHS goes white momentarily, and from portrait to landscape, the bottom goes white momentarily. A hack, but increase the size of the dimming view to get around this.
    increasedSize.width *= 1.5;
    increasedSize.height *= 1.5;
    _dimmingView.frameSize = increasedSize;

    // There appears to be no transitionCoordinator available for this "transition". Therefore using the regular UIView animation, below.
    /*
    if([self.presentedViewController transitionCoordinator])
    {
        [[self.presentedViewController transitionCoordinator] animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
            recenterViewController();
        } completion:nil];
    }
    else
    {
        recenterViewController();
    }*/

    // 4/23/15; See [1]. Given that I've turned off resizing with the autoresizingMask, this has messed up the repositioning of the (x, y) coordinate of the presentedViewController. Make up for that here.
    [UIView animateWithDuration: coordinator.transitionDuration animations:^{
        // I'm assuming the size here refers to the entire window.
        CGPoint center = CGPointMake(size.width/2.0, size.height/2.0);
        self.presentedViewController.view.center = center;
    } completion:nil];
}

- (void)presentationTransitionWillBegin
{
    UIView* containerView = [self containerView];

    // 4/23/15; So, this seems to be related to my modal view resizing problem. When I disable autoresizesSubviews, I stop the resizing during the rotation. HOWEVER, this is at the price of two additional problems: (a) the (x, y) coordinate of the modal stops being changed during the rotation, and (b) the animation of the background (_dimmingView?) starts looking funky during the rotation. WHICH makes sense. The containerView size is the full window.
    //containerView.autoresizesSubviews = NO;

    UIViewController* presentedViewController = [self presentedViewController];

    // [1] 4/23/15; This is better. The _dimmingView animation is preserved. The (x, y) position of the presentedViewController, however isn't right after the rotation.
    presentedViewController.view.autoresizingMask = UIViewAutoresizingNone;

    [_dimmingView setFrame:[containerView bounds]];
    [_dimmingView setAlpha:0.0];

    [containerView insertSubview:_dimmingView atIndex:0];

    void (^setAlpha)() = ^{
        [_dimmingView setAlpha:1.0];
    };

    if([presentedViewController transitionCoordinator])
    {
        [[presentedViewController transitionCoordinator] animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
            setAlpha();
        } completion:nil];
    }
    else
    {
        setAlpha();
    }
}

- (void)dismissalTransitionWillBegin
{
    void (^resetAlpha)() = ^{
        [_dimmingView setAlpha:0.0];
    };

    if([[self presentedViewController] transitionCoordinator])
    {
        [[[self presentedViewController] transitionCoordinator] animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
            resetAlpha();
        } completion:nil];
    }
    else
    {
        resetAlpha();
    }
}

- (CGRect)frameOfPresentedViewInContainerView
{
    SPASLogDetail(@"frameOfPresentedViewInContainerView: %@", NSStringFromCGRect(self.currentFrame));
    return self.currentFrame;
}

- (void) setCurrentFrame:(CGRect)currentFrame
{
    _currentFrame = currentFrame;
    // This is the important part for changing the frame of the presented view controller *after* the view is presented. For some odd reason, its not right to change the frame of the containerView.
    self.presentedView.frame = currentFrame;
}

- (void) containerViewWillLayoutSubviews;
{
    SPASLogDetail(@"containerViewWillLayoutSubviews");
}

- (void)prepareDimmingView
{
    _dimmingView = [[UIView alloc] init];
    [_dimmingView setBackgroundColor:[UIColor colorWithWhite:0.0 alpha:0.4]];
    [_dimmingView setAlpha:0.0];

    //UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dimmingViewTapped:)];
    //[_dimmingView addGestureRecognizer:tap];
}

/*
- (void)dimmingViewTapped:(UIGestureRecognizer *)gesture
{
    if([gesture state] == UIGestureRecognizerStateRecognized)
    {
        [[self presentingViewController] dismissViewControllerAnimated:YES completion:NULL];
    }
}*/

@end

@interface ChangeFrameTransitioningDelegate()
@property (nonatomic, strong) PresentationController *presentationController;
@end

@implementation ChangeFrameTransitioningDelegate

- (instancetype) init;
{
    self = [super init];
    return self;
}

- (UIPresentationController *)presentationControllerForPresentedViewController:(UIViewController *)presented presentingViewController:(UIViewController *)presenting sourceViewController:(UIViewController *)source
{
    self.presentationController = [[PresentationController alloc] initWithPresentedViewController:presented presentingViewController:presenting];
    self.presentationController.currentFrame = self.viewControllerFrame;

    return self.presentationController;
}

- (void) setViewControllerFrame:(CGRect)viewControllerFrame
{
    _viewControllerFrame = viewControllerFrame;
    self.presentationController.currentFrame = viewControllerFrame;
}

@end