我想在动画完成之前停用按钮。 我希望它在动画结束时处于活动状态。
我写了以下内容,但没有奏效。 它立即激活。
<%= @post.elements.each do |element|%>
<% if element.persisted?%>
<%= form_with(model: [@post, element]) do |form|%>
<%= form.text_area :content %>
<%= form.submit "save", class: 'btn btn-primary'%>
<%end%>
<%end%>
答案 0 :(得分:4)
SwiftUI 动画没有完成处理程序,但您可以监视可动画属性的状态并监听其更改。这可以满足您的需求,并且与动画的时间无关
SwiftUI 具有 AnimatableModifier
,您可以使用它来创建在动画完成时调用函数的修饰符。
您可以在 Except
看到对此的解释struct ContentView: View {
@State private var scale: CGFloat = 1
@State private var isDisable = false
var body: some View {
VStack {
Button(
action: {
self.isDisable = true
withAnimation(
.linear(duration: 1)
) {
scale = scale - 0.1
}
},
label: {
Text("Tap Me")
}
)
.disabled(
isDisable
)
RectangleView()
.scaleEffect(scale)
.onAnimationCompleted(for: scale) {
isDisable = false
}
}
}
}
struct RectangleView: View {
var body: some View {
Rectangle().fill(
Color.blue
)
.frame(
width:200,
height: 150
)
}
}
/// An animatable modifier that is used for observing animations for a given animatable value.
struct AnimationCompletionObserverModifier<Value>: AnimatableModifier where Value: VectorArithmetic {
/// While animating, SwiftUI changes the old input value to the new target value using this property. This value is set to the old value until the animation completes.
var animatableData: Value {
didSet {
notifyCompletionIfFinished()
}
}
/// The target value for which we're observing. This value is directly set once the animation starts. During animation, `animatableData` will hold the oldValue and is only updated to the target value once the animation completes.
private var targetValue: Value
/// The completion callback which is called once the animation completes.
private var completion: () -> Void
init(observedValue: Value, completion: @escaping () -> Void) {
self.completion = completion
self.animatableData = observedValue
targetValue = observedValue
}
/// Verifies whether the current animation is finished and calls the completion callback if true.
private func notifyCompletionIfFinished() {
guard animatableData == targetValue else { return }
/// Dispatching is needed to take the next runloop for the completion callback.
/// This prevents errors like "Modifying state during view update, this will cause undefined behavior."
DispatchQueue.main.async {
self.completion()
}
}
func body(content: Content) -> some View {
/// We're not really modifying the view so we can directly return the original input value.
return content
}
}
extension View {
/// Calls the completion handler whenever an animation on the given value completes.
/// - Parameters:
/// - value: The value to observe for animations.
/// - completion: The completion callback to call once the animation completes.
/// - Returns: A modified `View` instance with the observer attached.
func onAnimationCompleted<Value: VectorArithmetic>(for value: Value, completion: @escaping () -> Void) -> ModifiedContent<Self, AnimationCompletionObserverModifier<Value>> {
return modifier(AnimationCompletionObserverModifier(observedValue: value, completion: completion))
}
}
答案 1 :(得分:2)
添加延迟。
{
isDisable = true
withAnimation(
.linear(duration: 1)
) {
scale = scale - 0.1
}
DispatchQueue.main.asyncAfter(deadline: .now() + 1) { //< Here
isDisable = false
}
}
答案 2 :(得分:1)
Button {
let duration: Double = 1
isDisable = true
DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
isDisable = false
}
withAnimation(.linear(duration: duration)) {
scale -= 0.1
}
} label: {
Text("Tap Me")
}