我有一个带有可拖动组件（“弹性”文本）的屏幕，该组件在以非常突出的弹簧动画释放时会弹回。
有一些文本是异步进入的（在本例中，使用 a Timer），我希望它能够很好地淡入，同时 Springy 标签平滑地向上移动以为它腾出空间。
我在 VStack 中添加了一个动画，当异步加载的文本淡入时，它会按照我的意愿转换。但是，这会破坏“Springy”文本上的弹簧动画。
这里有一个注释掉的动画，如果将 1 秒动画切换到该位置，异步加载的文本会淡入，但在动画开始时，“有弹性”的文本会向上跳而不是向上滑动。
我怎样才能让两个动画都按照我的意愿工作？
import SwiftUI
import Combine
class Store: ObservableObject {
@Published var showSection: Bool = false
private var cancellables: [AnyCancellable] = []
init() {
Timer
.publish(every: 2, on: RunLoop.main, in: .common)
.autoconnect()
.map { _ in true}
.assign(to: \.showSection,
on: self)
.store(in: &cancellables)
}
}
struct ContentView: View {
@ObservedObject var store = Store()
@State var draggedState = CGSize.zero
var body: some View {
VStack {
Spacer()
VStack(alignment: .leading) {
VStack(spacing: 4) {
HStack {
Text("Springy")
.font(.title)
Image(systemName: "hand.point.up.left.fill")
.imageScale(.large)
}
.offset(x: draggedState.width, y: draggedState.height)
.foregroundColor(.secondary)
.gesture(
DragGesture().onChanged { value in
draggedState = value.translation
}
.onEnded { value in
// How can this animation be fast without the other animation slowing it down?
withAnimation(Animation
.interactiveSpring(response: 0.3,
dampingFraction: 0.1,
blendDuration: 0)) {
draggedState = .zero
}
}
)
VStack {
if store.showSection {
Text("Something that animates in after loading asynchrously.")
.font(.body)
.padding()
.transition(.opacity)
}
}
// When the animation is here, it doesn't cancel out the spring animation, but the Springy text jumps up at the beginning of the animation instead of animating.
// .animation(.easeInOut(duration: 1))
}
// Animation here has desired effect for loading, but overrides the Springy release animation.
.animation(.easeInOut(duration: 1))
}
Spacer()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
.preferredColorScheme(.dark)
}
}
扩展问题，基于 Asperi 的回答。
现在，假设我在这个 main 中有多个元素VStack，我想在它们进入时对其进行动画处理。
- 为我想要动画的每个部分添加一个单独的
.animation修改器是一个很好的解决方案吗？value
在下面的扩展示例中，这部分是：
.animation(.easeInOut(duration: 1),
value: store.showSection)
.animation(.easeInOut(duration: 1),
value: store.somePossibleText)
.animation(.easeInOut(duration: 1),
value: store.moreInformation)
- 我在这里使用 3 种方法来确定是否显示一个部分。为了简单起见，我在最初的示例中使用，但在我的实际场景中，我认为使用该方法而不是设置单独的或检查空字符串
Bool是最有意义的。在动画方面使用它是否有缺点，或者这样好吗？考虑到 Asperi 的解决方案，它似乎在这个例子中运行良好。String?Bool
这是带有新修改的完整示例：
import SwiftUI
import Combine
class Store: ObservableObject {
@Published var showSection: Bool = false
@Published var somePossibleText: String = ""
@Published var moreInformation: String?
private var cancellables: [AnyCancellable] = []
init() {
Timer
.publish(every: 2, on: RunLoop.main, in: .common)
.autoconnect()
.map { _ in true }
.assign(to: \.showSection,
on: self)
.store(in: &cancellables)
Timer
.publish(every: 3, on: RunLoop.main, in: .common)
.autoconnect()
.map { _ in "Something else loaded later" }
.assign(to: \.somePossibleText,
on: self)
.store(in: &cancellables)
Timer
.publish(every: 4, on: RunLoop.main, in: .common)
.autoconnect()
.map { _ in "More stuff loaded later" }
.assign(to: \.moreInformation,
on: self)
.store(in: &cancellables)
}
}
struct ContentView: View {
@ObservedObject var store = Store()
@State var draggedState = CGSize.zero
var body: some View {
VStack {
Spacer()
VStack(alignment: .leading) {
VStack(spacing: 4) {
HStack {
Text("Springy")
.font(.title)
Image(systemName: "hand.point.up.left.fill")
.imageScale(.large)
}
.offset(x: draggedState.width,
y: draggedState.height)
.foregroundColor(.secondary)
.gesture(
DragGesture().onChanged { value in
draggedState = value.translation
}
.onEnded { value in
// TODO: how can this animation be fast without the other one slowing it down?
withAnimation(Animation
.interactiveSpring(response: 0.3,
dampingFraction: 0.1,
blendDuration: 0)) {
draggedState = .zero
}
}
)
if store.showSection {
Text("Something that animates in after loading asynchrously.")
.font(.body)
.padding()
.transition(.opacity)
}
if store.somePossibleText != "" {
Text(store.somePossibleText)
.font(.footnote)
.padding()
.transition(.opacity)
}
if let moreInformation = store.moreInformation {
Text(moreInformation)
.font(.footnote)
.padding()
.transition(.opacity)
}
}
.animation(.easeInOut(duration: 1),
value: store.showSection)
.animation(.easeInOut(duration: 1),
value: store.somePossibleText)
.animation(.easeInOut(duration: 1),
value: store.moreInformation)
}
Spacer()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
.preferredColorScheme(.dark)
}
}