3D 触摸/强制触摸实现
Posted
技术标签:
【中文标题】3D 触摸/强制触摸实现【英文标题】：3D touch/Force touch implementation 【发布时间】：2015-09-24 22:27:44 【问题描述】：我们如何实现 3D 触摸来检查用户是否点击UIView 或强制触摸UIView？
有没有办法使用UIGestureRecognize 或仅使用UITouch 来做到这一点？
【问题讨论】：
【参考方案1】：您可以在没有指定手势识别器的情况下执行此操作。您无需调整 touchesEnded 和 touchesBegan 方法，只需调整 touchesMoved 即可获得正确的值。从开始/结束获取 uitouch 的力量将返回奇怪的值。
UITouch *touch = [touches anyObject];
CGFloat maximumPossibleForce = touch.maximumPossibleForce;
CGFloat force = touch.force;
CGFloat normalizedForce = force/maximumPossibleForce;
然后，设置一个力阈值并将 normalizedForce 与此阈值进行比较（0.75 对我来说似乎很好）。
【讨论】：
【参考方案2】：3D Touch 属性are available on UITouch objects。
您可以通过覆盖UIView 的touchesBegan: 和touchesMoved: 方法来实现这些功能。不确定你在touchesEnded: 看到了什么。
如果您愿意创建新的手势识别器，您可以完全访问 UIGestureRecognizerSubclass 中公开的 UITouches。
我不确定如何在传统的UIGestureRecognizer 中使用 3D 触摸属性。也许通过UIGestureRecognizerDelegate 协议的gestureRecognizer:shouldReceiveTouch: 方法。
【讨论】：
我想检查用户是否点击 UIView 或强制触摸 UIViewUITapGestureRecognizer 尚未针对 3D Touch 进行更新，因此您必须创建自己的 UIGestureRecognizer 子类或子类视图并处理 touchesBegan 和 touchesMoved。
如果触摸不动但力度发生变化，touchesMoved: 会被调用吗？【参考方案3】：
在 Swift 4.2 和 ios 12 中，解决问题的一种可能方法是创建 UIGestureRecognizer 的自定义子类来处理 Force Touch，并将其添加到 UITapGestureRecognizer 旁边的视图中。下面的完整代码展示了如何实现它：
ViewController.swift
import UIKit
class ViewController: UIViewController
let redView = UIView()
lazy var tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(tapHandler))
lazy var forceTouchGestureRecognizer = ForceTouchGestureRecognizer(target: self, action: #selector(forceTouchHandler))
override func viewDidLoad()
super.viewDidLoad()
redView.backgroundColor = .red
redView.addGestureRecognizer(tapGestureRecognizer)
view.addSubview(redView)
redView.translatesAutoresizingMaskIntoConstraints = false
redView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
redView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
redView.widthAnchor.constraint(equalToConstant: 100).isActive = true
redView.heightAnchor.constraint(equalToConstant: 100).isActive = true
override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?)
super.traitCollectionDidChange(previousTraitCollection)
if traitCollection.forceTouchCapability == UIForceTouchCapability.available
redView.addGestureRecognizer(forceTouchGestureRecognizer)
else
// When force touch is not available, remove force touch gesture recognizer.
// Also implement a fallback if necessary (e.g. a long press gesture recognizer)
redView.removeGestureRecognizer(forceTouchGestureRecognizer)
@objc func tapHandler(_ sender: UITapGestureRecognizer)
print("Tap triggered")
@objc func forceTouchHandler(_ sender: ForceTouchGestureRecognizer)
UINotificationFeedbackGenerator().notificationOccurred(.success)
print("Force touch triggered")
ForceTouchGestureRecognizer.swift
import UIKit.UIGestureRecognizerSubclass
@available(iOS 9.0, *)
final class ForceTouchGestureRecognizer: UIGestureRecognizer
private let threshold: CGFloat = 0.75
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent)
super.touchesBegan(touches, with: event)
if let touch = touches.first
handleTouch(touch)
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent)
super.touchesMoved(touches, with: event)
if let touch = touches.first
handleTouch(touch)
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent)
super.touchesEnded(touches, with: event)
state = UIGestureRecognizer.State.failed
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent)
super.touchesCancelled(touches, with: event)
state = UIGestureRecognizer.State.failed
private func handleTouch(_ touch: UITouch)
guard touch.force != 0 && touch.maximumPossibleForce != 0 else return
if touch.force / touch.maximumPossibleForce >= threshold
state = UIGestureRecognizer.State.recognized
来源：
GitHub / FlexMonkey - DeepPressGestureRecognizer
GitHub / ashleymills - ForceTouchGestureRecognizer
Apple Developer Documentation - Implementing a Discrete Gesture Recognizer
【讨论】：
【参考方案4】：我创建了一个模拟 Apple Mail 应用程序行为的 UIGestureRecognizer。在 3D 触摸时，它以一个短的单脉冲振动开始，然后是一个可选的辅助动作 (hardTarget)，并在初始按下后不久通过硬按下调用脉冲。
改编自https://github.com/FlexMonkey/DeepPressGestureRecognizer
变化：
3D 触摸振动脉冲类似于 iOS 系统行为 必须先触摸才能结束，例如 Apple 邮件应用程序 阈值默认为系统默认级别 硬触摸触发类似邮件应用的 hardAction 调用注意：我添加了未记录的系统声音 k_PeakSoundID，但如果您对使用超出记录范围的常数感到不舒服，请随时将其关闭。多年来，我一直在使用具有未公开常量的系统声音，但欢迎您使用 vibrateOnDeepPress 属性关闭振动脉冲。
import UIKit
import UIKit.UIGestureRecognizerSubclass
import AudioToolbox
class DeepPressGestureRecognizer: UIGestureRecognizer
var vibrateOnDeepPress = true
var threshold: CGFloat = 0.75
var hardTriggerMinTime: TimeInterval = 0.5
var onDeepPress: (() -> Void)?
private var deepPressed: Bool = false
didSet
if (deepPressed && deepPressed != oldValue)
onDeepPress?()
private var deepPressedAt: TimeInterval = 0
private var k_PeakSoundID: UInt32 = 1519
private var hardAction: Selector?
private var target: AnyObject?
required init(target: AnyObject?, action: Selector, hardAction: Selector? = nil, threshold: CGFloat = 0.75)
self.target = target
self.hardAction = hardAction
self.threshold = threshold
super.init(target: target, action: action)
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent)
if let touch = touches.first
handle(touch: touch)
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent)
if let touch = touches.first
handle(touch: touch)
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent)
super.touchesEnded(touches, with: event)
state = deepPressed ? UIGestureRecognizerState.ended : UIGestureRecognizerState.failed
deepPressed = false
private func handle(touch: UITouch)
guard let _ = view, touch.force != 0 && touch.maximumPossibleForce != 0 else
return
let forcePercentage = (touch.force / touch.maximumPossibleForce)
let currentTime = Date.timeIntervalSinceReferenceDate
if !deepPressed && forcePercentage >= threshold
state = UIGestureRecognizerState.began
if vibrateOnDeepPress
AudioServicesPlaySystemSound(k_PeakSoundID)
deepPressedAt = Date.timeIntervalSinceReferenceDate
deepPressed = true
else if deepPressed && forcePercentage <= 0
endGesture()
else if deepPressed && currentTime - deepPressedAt > hardTriggerMinTime && forcePercentage == 1.0
endGesture()
if vibrateOnDeepPress
AudioServicesPlaySystemSound(k_PeakSoundID)
//fire hard press
if let hardAction = self.hardAction, let target = self.target
_ = target.perform(hardAction, with: self)
func endGesture()
state = UIGestureRecognizerState.ended
deepPressed = false
// MARK: DeepPressable protocol extension
protocol DeepPressable
var gestureRecognizers: [UIGestureRecognizer]? get set
func addGestureRecognizer(gestureRecognizer: UIGestureRecognizer)
func removeGestureRecognizer(gestureRecognizer: UIGestureRecognizer)
func setDeepPressAction(target: AnyObject, action: Selector)
func removeDeepPressAction()
extension DeepPressable
func setDeepPressAction(target: AnyObject, action: Selector)
let deepPressGestureRecognizer = DeepPressGestureRecognizer(target: target, action: action, threshold: 0.75)
self.addGestureRecognizer(gestureRecognizer: deepPressGestureRecognizer)
func removeDeepPressAction()
guard let gestureRecognizers = gestureRecognizers else return
for recogniser in gestureRecognizers where recogniser is DeepPressGestureRecognizer
removeGestureRecognizer(gestureRecognizer: recogniser)
【讨论】：
将振动代码放入识别器可能是架构错误。 仅适用于 iOS 15，不适用于以前的 iOS 版本，如 14、13、12. ....【参考方案5】：我这样做的方式是结合使用UITapGestureRecognizer（Apple 提供）和DFContinuousForceTouchGestureRecognizer（我提供）。
DFContinuousForceTouchGestureRecognizer 很好，因为它提供了有关压力变化的持续更新，因此您可以在用户改变压力时执行诸如增强视图之类的操作，而不是单个事件。如果您只想要一个事件，您可以忽略 DFContinuousForceTouchDelegate 中的所有内容，除了 - (void) forceTouchRecognized 回调。
https://github.com/foggzilla/DFContinuousForceTouchGestureRecognizer
您可以下载这个并在支持力压的设备上运行示例应用，看看感觉如何。
在您的 UIViewController 中执行以下操作：
- (void)viewDidLoad
[super viewDidLoad];
_forceTouchRecognizer = [[DFContinuousForceTouchGestureRecognizer alloc] init];
_forceTouchRecognizer.forceTouchDelegate = self;
//here to demonstrate how this works alonside a tap gesture recognizer
_tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapped:)];
[self.imageView addGestureRecognizer:_tapGestureRecognizer];
[self.imageView addGestureRecognizer:_forceTouchRecognizer];
为点击手势实现选择器
#pragma UITapGestureRecognizer selector
- (void)tapped:(id)sender
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^
[[[UIAlertView alloc] initWithTitle:@"Tap" message:@"YEAH!!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
);
实现强制触摸的委托协议：
#pragma DFContinuousForceTouchDelegate
- (void)forceTouchRecognized:(DFContinuousForceTouchGestureRecognizer *)recognizer
self.imageView.transform = CGAffineTransformIdentity;
[self.imageView setNeedsDisplay];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^
[[[UIAlertView alloc] initWithTitle:@"Force Touch" message:@"YEAH!!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
);
- (void)forceTouchRecognizer:(DFContinuousForceTouchGestureRecognizer *)recognizer didStartWithForce:(CGFloat)force maxForce:(CGFloat)maxForce
CGFloat transformDelta = 1.0f + ((force/maxForce) / 3.0f);
self.imageView.transform = CGAffineTransformMakeScale(transformDelta, transformDelta);
[self.imageView setNeedsDisplay];
- (void) forceTouchRecognizer:(DFContinuousForceTouchGestureRecognizer *)recognizer didMoveWithForce:(CGFloat)force maxForce:(CGFloat)maxForce
CGFloat transformDelta = 1.0f + ((force/maxForce) / 3.0f);
self.imageView.transform = CGAffineTransformMakeScale(transformDelta, transformDelta);
[self.imageView setNeedsDisplay];
- (void)forceTouchRecognizer:(DFContinuousForceTouchGestureRecognizer *)recognizer didCancelWithForce:(CGFloat)force maxForce:(CGFloat)maxForce
self.imageView.transform = CGAffineTransformIdentity;
[self.imageView setNeedsDisplay];
- (void)forceTouchRecognizer:(DFContinuousForceTouchGestureRecognizer *)recognizer didEndWithForce:(CGFloat)force maxForce:(CGFloat)maxForce
self.imageView.transform = CGAffineTransformIdentity;
[self.imageView setNeedsDisplay];
- (void)forceTouchDidTimeout:(DFContinuousForceTouchGestureRecognizer *)recognizer
self.imageView.transform = CGAffineTransformIdentity;
[self.imageView setNeedsDisplay];
请注意，这仅在支持强制触摸的设备上有用。
此外，如果您在 iOS 8 或更低版本上运行，则不应将 DFContinuousForceTouchGestureRecognizer 添加到视图中，因为它使用 UITouch 上的新 force 属性，仅在 iOS 9 中可用。
如果您在 iOS 8 上添加它会崩溃，因此如果您支持的版本早于 iOS 9，请根据您运行的 iOS 版本有条件地添加此识别器。
【讨论】：
哇，谢谢！你能把你的答案转换成 Swift 2.0 吗？而且我的应用支持 iOS 8 - 9 所以我不需要添加 DFContinuousForceTouchGestureRecognizer 来查看以上是关于3D 触摸/强制触摸实现的主要内容，如果未能解决你的问题，请参考以下文章
Swift：实现快捷方式项目（3D 触摸）共享项目错误“AppDelegate 类型的值没有当前成员”
android实现3D Gallery 轮播效果，触摸时停止轮播