问题描述
我想识别同一项目上的 TapGesture 和 LongPressGesture。它工作正常，但有以下例外：LongPressGesture 单独在我指定的持续时间（0.25 秒）后响应，但是当我将它与 TapGesture 结合时，它至少需要 1 秒——我找不到办法让它反应更快。这是一个演示：
这是它的代码：
struct ContentView: View {
@State var message = ""
var body: some View {
Circle()
.fill(Color.yellow)
.frame(width: 150,height: 150)
.onTapGesture(count: 1) {
message = "TAP"
}
.onLongPressGesture(minimumDuration: 0.25) {
message = "LONG\nPRESS"
}
.overlay(Text(message)
.font(.title).bold()
.multilineTextAlignment(.center)
.allowsHitTesting(false))
}
}
请注意，除了 LongPress 的持续时间（远长于 0.25 秒）之外，它工作正常。
有什么想法吗？提前致谢！
解决方法
为了在项目中拥有一些适合每个人需要的多手势，Apple 没有什么比普通手势更能提供的了，将它们混合在一起以达到想要的手势有时会变得棘手，这是一种拯救，没有 > 问题或错误！
这里有一个名为 interactionReader 的自定义零问题手势，我们可以将其应用于任何视图。在同时拥有LongPressGesture和TapGesture。
import SwiftUI
struct ContentView: View {
var body: some View {
Circle()
.fill(Color.yellow)
.frame(width: 150,height: 150)
.interactionReader(longPressSensitivity: 250,tapAction: tapAction,longPressAction: longPressAction,scaleEffect: true)
.animation(Animation.easeInOut(duration: 0.2))
}
func tapAction() { print("tap action!") }
func longPressAction() { print("longPress action!") }
}
struct InteractionReaderViewModifier: ViewModifier {
var longPressSensitivity: Int
var tapAction: () -> Void
var longPressAction: () -> Void
var scaleEffect: Bool = true
@State private var isPressing: Bool = Bool()
@State private var currentDismissId: DispatchTime = DispatchTime.now()
@State private var lastInteractionKind: String = String()
func body(content: Content) -> some View {
let processedContent = content
.gesture(gesture)
.onChange(of: isPressing) { newValue in
currentDismissId = DispatchTime.now() + .milliseconds(longPressSensitivity)
let dismissId: DispatchTime = currentDismissId
if isPressing {
DispatchQueue.main.asyncAfter(deadline: dismissId) {
if isPressing { if (dismissId == currentDismissId) { lastInteractionKind = "longPress"; longPressAction() } }
}
}
else {
if (lastInteractionKind != "longPress") { lastInteractionKind = "tap"; tapAction() }
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(50)) {lastInteractionKind = "none"}
}
}
return Group {
if scaleEffect { processedContent.scaleEffect(lastInteractionKind == "longPress" ? 1.5: (lastInteractionKind == "tap" ? 0.8 : 1.0 )) }
else { processedContent }
}
}
var gesture: some Gesture {
DragGesture(minimumDistance: 0.0,coordinateSpace: .local)
.onChanged() { _ in if !isPressing { isPressing = true } }
.onEnded() { _ in isPressing = false }
}
}
extension View {
func interactionReader(longPressSensitivity: Int,tapAction: @escaping () -> Void,longPressAction: @escaping () -> Void,scaleEffect: Bool = true) -> some View {
return self.modifier(InteractionReaderViewModifier(longPressSensitivity: longPressSensitivity,scaleEffect: scaleEffect))
}
}
LongPressGesture 有另一个完成功能，可以在用户第一次触地时执行一个动作......并在最短的持续时间内再次触地。像这样的东西可以工作吗？
struct LongTapTest: View {
@State var message = ""
var body: some View {
Circle()
.fill(Color.yellow)
.frame(width: 150,height: 150)
.onLongPressGesture(minimumDuration: 0.25,maximumDistance: 50,pressing: { (isPressing) in
if isPressing {
// called on touch down
} else {
// called on touch up
message = "TAP"
}
},perform: {
message = "LONG\nPRESS"
})
.overlay(Text(message)
.font(.title).bold()
.multilineTextAlignment(.center)
.allowsHitTesting(false))
}
}
嗯，这并不漂亮，但效果很好。它记录每次点击/按下的开始，如果它在 0.25 秒之前结束，则将其视为 TapGesture，否则将其视为 LongPressGesture：
struct ContentView: View {
@State var pressInProgress = false
@State var gestureEnded = false
@State var workItem: DispatchWorkItem? = nil
@State var message = ""
var body: some View {
Circle()
.fill(Color.yellow)
.frame(width: 150,height: 150,alignment: .center)
.overlay(Text(message)
.font(.title).bold()
.multilineTextAlignment(.center)
.allowsHitTesting(false))
.gesture(
DragGesture(minimumDistance: 0,coordinateSpace: .global)
.onChanged { _ in
guard !pressInProgress else { return }
pressInProgress = true
workItem = DispatchWorkItem {
message = "LONG\nPRESSED"
gestureEnded = true
}
DispatchQueue.main.asyncAfter(deadline: .now() + 0.25,execute: workItem!)
}
.onEnded { _ in
pressInProgress = false
workItem?.cancel()
guard !gestureEnded else { // moot if we're past 0.25 seconds so ignore
gestureEnded = false
return
}
message = "TAPPED"
gestureEnded = false
}
)
}
}
如果有人能想到一个实际使用 LongPressGesture 和 TapGesture 的解决方案，我更喜欢那个！