ScrollView中的动画不起作用？使用Xcode 11 beta 6 [英] Animation in ScrollView is not working ? Using Xcode 11 beta 6

问题描述

我试图制作ScrollView过渡动画，但发现在scrollView中它们的工作方式有所不同。但是仍然无法在其中做动画。我正在提供代码，请看一看。使用Xcode 11 beta 6

I was trying to to do transition animation Scrollview but found out that how things work differently in scrollView. But still unable to do animation in it. I am providing code, please have a look. Using Xcode 11 beta 6

import SwiftUI 

struct ContentView : View {

@State private var isButtonVisible = false

var body: some View {

    NavigationView {
        ScrollView{
            VStack {
                Button(action: {
                 //   withAnimation {
                        self.isButtonVisible.toggle()
                  //   }
                }) {
                    Text("Press me")
                }

                if isButtonVisible {
                        Text("sss")

                            .frame(height: true ? 50 : 0, alignment: .center)
                              .background(Color.red)
                            .animation(.linear(duration: 2))
                      //  .transition(.move(edge: .top))

                }
            }

        }

    }


}}

推荐答案

这肯定是一个错误，我建议您向Apple提交错误报告。我找到了一种解决方法（请参见下面的代码），但是不幸的是它发现了另一个错误！

This must be a bug, and I suggest you file a bug report with Apple. I find a workaround (see code below), but it unfortunately uncovers another bug!

为了使ScrollView中的动画正常工作，您可以将内容封装在自定义视图。

In order to make the animation inside the ScrollView to work, you can encapsulate the contents in a custom view. That will fix that problem.

这将发现一个新问题，这可以从我添加到代码中的边框中看出：添加文本视图时，它会移动

This will uncover a new issue, which is made evident by the borders I added to your code: when the Text view is added, it shifts parts of the contents outside the ScrollView.

您会发现这是不正确的。尝试使用默认值isButtonVisible = true启动您的应用程序，您会看到它以不同的方式呈现。

You will see that this is not correct. Try starting your app with a default value isButtonVisible = true, and you will see it renders it differently.

struct ContentView : View {
    var body: some View {
        NavigationView {
            ScrollView {
                EncapsulatedView().border(Color.green)
            }.border(Color.blue)
        }
    }
}

struct EncapsulatedView: View {
    @State private var isButtonVisible = false

    var body: some View {
        VStack {
            Text("Filler")
            Button(action: {
                withAnimation(.easeInOut(duration: 2.0)) {
                    self.isButtonVisible.toggle()
                }
            }) {
                Text("Press me")
            }

            if isButtonVisible {
                Text("sss")
                    .frame(height: true ? 50 : 0, alignment: .center)
                    .transition(.opacity)
                    .background(Color.red)
            }
            Spacer()
        }.border(Color.red)
    }
}

这篇关于ScrollView中的动画不起作用？使用Xcode 11 beta 6的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！