本文介绍了如何在IOS底部从底部显示模态UIViewController对话框(如下图)的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
如何呈现一个模态的UIViewController(从Storyboard中说)，并从呈现的视图控制器的底部向上滑动.要求是:
How would one present a UIViewController (from Storyboard say) that is modal, and slides up from the bottom of the presenting view controller. Requirements would be:
- 从底部向上滑动，宽度与当前视图控制器的宽度对齐
- 不占用整个屏幕或整个父级呈现视图控制器(仅显示自身所需的高度)
- 可以在不占据整个屏幕的视图控制器的上下文中显示
推荐答案
我不使用情节提要，所以我将其全部写下来.您可以将其复制粘贴到一个全新的项目中，然后运行它以查看其工作情况.
I do not use storyboards so I wrote it all out. You can copy paste this into a brand new project and run it to see it working.
您的PresentingController需要符合两件事.第一个协议是:UIViewControllerTransitioningDelegate，它允许控制器提供一个自定义的演示者(在下面的示例中就是它自己).无论您在此处返回的内容是什么(自身或其他对象)，都需要符合UIViewControllerAnimatedTransitioning并提供自定义动画.对于这个独立的示例，我选择当前的viewController作为演示者和动画设计师.
Your PresentingController needs to conform to two things. The first protocol is: UIViewControllerTransitioningDelegate which allows the controller to provide a custom presenter (namely itself in our case below). Whatever you return here (be it self, or some other object) needs to conform to UIViewControllerAnimatedTransitioning and provide the custom animations. For this self-contained example, I chose the current viewController to be the presenter and animator.
接下来，它需要符合协议:UIViewControllerAnimatedTransitioning，该协议为所有显示或关闭的控制器提供自定义动画.
Next, it needs to conform to protocol: UIViewControllerAnimatedTransitioning which provides the custom animation for any presenting or dismissing controllers.
换句话说，当我们显示或关闭viewController时，将调用UIViewControllerAnimatedTransitioning协议中的animateTransition来确定子控制器应如何动画化为透视图或从视口中退出.
In other words, when we present or dismiss a viewController, animateTransition from the UIViewControllerAnimatedTransitioning protocol will be called to determine how the child controller should animate into perspective or dismiss from the view-port.
示例(带有过渡动画)
//
// ViewController.m
// SO
//
// Created by Brandon T on 2017-01-23.
// Copyright © 2017 XIO. All rights reserved.
//
#import "ViewController.h"
//Some view controller that will be presented modally.
//I have coloured it red.
@interface ModalController : UIViewController
@end
@implementation ModalController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor redColor];
}
@end
//The view controller that will present or dismiss some other view controller modally.
//I have coloured it white.
@interface ViewController () <UIViewControllerTransitioningDelegate, UIViewControllerAnimatedTransitioning>
@property (nonatomic, assign) bool presentingModalController;
@property (nonnull, nonatomic, strong) ModalController *modalController;
@property (nonnull, nonatomic, strong) UIButton *button;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
//For this example, I add a button to present and dismiss the redViewController.
self.button = [[UIButton alloc] initWithFrame:CGRectMake(15, self.view.center.y - 100, self.view.frame.size.width - 30, 45)];
[self.button setTitle:@"Present" forState:UIControlStateNormal];
[self.button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[self.button setBackgroundColor:[UIColor lightGrayColor]];
[self.button.layer setCornerRadius:5.0];
[self.button addTarget:self action:@selector(onButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:self.button];
//Create the redViewController and set its transitioning delegate to self (this controller will be providing the animation and presenter).
//We also set the style to OverFullScreen because we don't want this controller to disappear.
//When a view controller is presented, the one that presented it usually disappears or gets removed from the hierarchy until the child is dismissed. In the case of alerts, or controllers that need to display OVER the current one, we need to set the modalPresentationStyle.
self.modalController = [[ModalController alloc] init];
self.modalController.transitioningDelegate = self;
self.modalController.modalPresentationStyle = UIModalPresentationOverFullScreen;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)onButtonClicked:(UIButton *)button {
if (self.modalController.view.window == nil) {
[self presentViewController:self.modalController animated:YES completion:nil];
[self.button setTitle:@"Dismiss" forState:UIControlStateNormal];
//not a good idea but meh.. I need to keep this example short.
[self.view.window addSubview:self.button];
}
else {
[self.modalController dismissViewControllerAnimated:YES completion:nil];
[self.button setTitle:@"Present" forState:UIControlStateNormal];
[self.view addSubview:self.button];
}
}
//Custom Animations and Presenters.
- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source {
self.presentingModalController = true; //We are presenting the controller.
return self; //Who is animating it? We are.
}
- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
self.presentingModalController = false; //We are dismissing the view controller.
return self; //Who animated it? We did.
}
//How fast should it present? I chose 0.5 seconds.
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext {
return 0.5;
}
//The actual animation code.
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext {
if (self.presentingModalController) {
//If we are presenting, we need to add the new controller's view as a sub-view.
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
//We need a starting frame for the animation.
CGRect startingFrame = transitionContext.containerView.bounds;
startingFrame.origin.y = startingFrame.size.height; //Starts from the bottom of the parent.
startingFrame.size.height = 100; //Has a height of 100.
//We need an end frame for the animation.
CGRect finalFrame = transitionContext.containerView.bounds;
finalFrame.origin.y = finalFrame.size.height - 100; //100 from the bottom of the parent.
finalFrame.size.height = 100; //Present with a size of 100 height.
//Add the controller's view as a subview of the context.
[transitionContext.containerView addSubview:toViewController.view];
[toViewController.view setFrame:startingFrame];
//Start animating from "startFrame" --> "endFrame" with 0.5 seconds duration and no delay. I chose easeIn style.
[UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0.0 options:UIViewAnimationOptionCurveEaseIn animations:^{
[toViewController.view setFrame:finalFrame];
} completion:^(BOOL finished) {
//We are finished animating, complete the transition!
[transitionContext completeTransition:YES];
}];
}
else {
//If we are dismissing the view controller, we need to animate it down the screen and then remove its view from the context.
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
//We only need one frame. This is the first frame. We are animating from "endFrame" --> "startingFrame" (backwards/reverse animation).
CGRect startingFrame = transitionContext.containerView.bounds;
startingFrame.origin.y = startingFrame.size.height; //Starts from the bottom of the parent.
startingFrame.size.height = 100; //Has a height of 100.
//Start the animation with 0.5 seconds duration and I chose easeOut style.
[UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
[fromViewController.view setFrame:startingFrame];
} completion:^(BOOL finished) {
//Remove the view controller's view from the context and complete the transition!
[fromViewController.view removeFromSuperview];
[transitionContext completeTransition:YES];
}];
}
}
@end
示例(不带过渡动画)
Example (Without Transition Animation):
//
// ViewController.m
// SO2
//
// Created by Brandon Thomas on 2017-01-23.
// Copyright © 2017 XIO. All rights reserved.
//
#import "ViewController.h"
@interface ModalController : UIViewController
@end
@implementation ModalController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor redColor];
}
@end
@interface ViewController ()
@property (nonatomic, assign) bool presentingModalController;
@property (nonnull, nonatomic, strong) ModalController *modalController;
@property (nonnull, nonatomic, strong) UIButton *button;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.button = [[UIButton alloc] initWithFrame:CGRectMake(15, self.view.center.y - 100, self.view.frame.size.width - 30, 45)];
[self.button setTitle:@"Present" forState:UIControlStateNormal];
[self.button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[self.button setBackgroundColor:[UIColor lightGrayColor]];
[self.button.layer setCornerRadius:5.0];
[self.button addTarget:self action:@selector(onButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:self.button];
self.modalController = [[ModalController alloc] init];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)onButtonClicked:(UIButton *)button {
if (self.modalController.view.window == nil) {
//Present
CGRect startingFrame = self.view.bounds;
startingFrame.origin.y = startingFrame.size.height; //Starts from the bottom of the parent.
startingFrame.size.height = 100; //Has a height of 100.
CGRect finalFrame = self.view.bounds;
finalFrame.origin.y = finalFrame.size.height - 100; //100 from the bottom of the parent.
finalFrame.size.height = 100; //Present with a size of 100 height.
[self.modalController.view setFrame:startingFrame];
[self.modalController willMoveToParentViewController:self];
[self addChildViewController:self.modalController];
[self.view addSubview:self.modalController.view];
[self.modalController didMoveToParentViewController:self];
[UIView animateWithDuration:0.5 animations:^{
[self.modalController.view setFrame:finalFrame];
} completion:^(BOOL finished) {
}];
}
else {
//Dismiss
CGRect startingFrame = self.view.bounds;
startingFrame.origin.y = startingFrame.size.height; //Starts from the bottom of the parent.
startingFrame.size.height = 100; //Has a height of 100.
[UIView animateWithDuration:0.5 animations:^{
[self.modalController.view setFrame:startingFrame];
} completion:^(BOOL finished) {
[self.modalController.view removeFromSuperview];
[self.modalController willMoveToParentViewController:nil];
[self.modalController removeFromParentViewController];
[self.modalController didMoveToParentViewController:nil];
}];
}
}
@end
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