我是iOS开发的新手。我目前需要开发一个ForceTouchGestureRecognizer,当用户开始触摸时激活2秒
但是,添加holdFor > minimumPressDuration
之后,强制触摸手势的状态确实很好
似乎.changed
一个州无法达成
有控制台输出
以下是ForceTouchGestureRecognizer类的代码
import UIKit
import UIKit.UIGestureRecognizerSubclass
class ForceTouchGestureRecognizer: UIGestureRecognizer {
var minimumValue: CGFloat = 0 // Value between 0.0 - 1.0 that needs to be reached before gesture begins
var tolerance: CGFloat = 1 // Once force drops below maxValue - tolerance, the gesture ends
var minimumPressDuration: Int = 1000
private(set) var forceValue: CGFloat? // value between 0.0 - 1.0
private var maxValue: CGFloat = 0
private var touchStartTime: Int = 0
override func reset() {
super.reset()
forceValue = nil
maxValue = 0
minimumPressDuration = 1500
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesBegan(touches, with: event)
if #available(iOS 9.0, *) {
if touches.count != 1 {
state = .failed
}
touchStartTime = Int(NSDate().timeIntervalSince1970 * 1000)
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if #available(iOS 9.0, *) {
let touch = touches.first!
let value = touch.force / touch.maximumPossibleForce
let holdFor = Int(NSDate().timeIntervalSince1970 * 1000) - touchStartTime
if state == .possible {
if value > minimumValue && holdFor > minimumPressDuration {
self.state = .began
}
} else {
if value < (maxValue - tolerance) {
state = .ended
} else {
maxValue = max(self.forceValue ?? 0, maxValue)
self.forceValue = value
state = .changed
}
}
}
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesCancelled(touches, with: event)
if state == .began || state == .changed {
state = .cancelled
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesEnded(touches, with: event)
if state == .began || state == .changed {
state = .ended
}
}
}
于2019年3月17日更新
根据Craz1k0ek的说法。我认为在这里发布我的工作代码会很好
import UIKit.UIGestureRecognizerSubclass
class ForceTouchGestureRecognizer: UIGestureRecognizer {
var minimumValue: CGFloat = 0 // Value between 0.0 - 1.0 that needs to be reached before gesture begins
var tolerance: CGFloat = 1 // Once force drops below maxValue - tolerance, the gesture ends
var minimumPressDuration: TimeInterval = 1.5
private(set) var forceValue: CGFloat? // value between 0.0 - 1.0
private var maxValue: CGFloat = 0
private var touchStartTime: TimeInterval?
override func reset() {
super.reset()
forceValue = nil
maxValue = 0
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesBegan(touches, with: event)
if #available(iOS 9.0, *) {
if touches.count != 1 {
state = .failed
}
touchStartTime = Date().timeIntervalSince1970
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
guard touchStartTime != nil else { return }
super.touchesMoved(touches, with: event)
if #available(iOS 9.0, *) {
let touch = touches.first!
let value = touch.force / touch.maximumPossibleForce
let holdFor = NSDate().timeIntervalSince1970 - touchStartTime!
if holdFor > minimumPressDuration {
if state == .possible {
if value > minimumValue {
self.state = .began
}
} else {
if value < (maxValue - tolerance) {
state = .ended
} else {
maxValue = max(self.forceValue ?? 0, maxValue)
self.forceValue = value
state = .changed
}
}
}
}
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesCancelled(touches, with: event)
if state == .began || state == .changed {
state = .cancelled
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesEnded(touches, with: event)
if state == .began || state == .changed {
state = .ended
}
}
}
我想引用documentation:
特殊注意事项UIGestureRecognizer的子类必须使用state属性的读写版本。他们在导入UIGestureRecognizerSubclass.h头文件时得到重新声明...
我已经简化了你的手势识别器,让它在两秒后激活。请注意,我发现代码中存在一些不一致:默认情况下,minimumPressDuration
设置为1000
,但是,reset()
将值设置为1500
,这也可能解释了您的一些行为。
class ForceTouchRecognizer: UIGestureRecognizer {
// The minimum time the touch should take
private let minimumTouchTime: TimeInterval = 2.0
// The start time of the touch
private var touchStartTime: TimeInterval?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
// Set the start time
touchStartTime = Date().timeIntervalSince1970
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
// If there is no start time, how is this possible, don't do anything
guard touchStartTime != nil else { return }
// Check if the minimumTouchTime has passed since the start time
if(Date().timeIntervalSince1970 - touchStartTime! > minimumTouchTime) {
print("I should perform some action now!")
}
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
// Make sure the start time is reset
touchStartTime = nil
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
// Make sure the start time is reset
touchStartTime = nil
}
}
我还建议看看UILongPressGestureRecognizer课程。这可能也有你想要的一些功能。