SwiftUI 在预览模式下使用按钮关闭模态

Question

我有一个简单的 Button，当它被点击时会打开一个 Modal。我知道可以通过向下滑动来关闭模态，但我实现了一个按钮来关闭它并且这有效。

唯一困扰我的是我无法预览我的模态框（看看下面我的代码）


// Button that opens the modal
struct ContentView: View {
  @State private var willMoveToNextScreen = false
  Button(action: {
          self.willMoveToNextScreen = true
     }, label: {
           Image(systemName: "gear")
                 .font(.system(size: 30))
                 .padding(.leading, 15)
            })
            .sheet(isPresented: $willMoveToNextScreen, content: {
                    SettingsView(willMoveToNextScreen: $willMoveToNextScreen)
     })
}


// Modal
 struct SettingsView: View {
     @Binding var willMoveToNextScreen: Bool
    
      var body: some View {
        VStack{
            HStack {
                Button(action: {
                    self.willMoveToNextScreen = false
                }, label: {
                    Image(systemName: "xmark")
                        .font(.system(size: 30, weight: .semibold))
                })
            }
            .frame(maxWidth: .infinity, alignment: .trailing)
            .padding(15)
            Spacer()
            Text("Aye")
        }
    }
}

struct SettingsView_Previews: PreviewProvider {
    static var previews: some View {
        // I don't know which value I should provide, it expects a Binding<Bool> value
        SettingsView(willMoveToNextScreen: ??) 
    }
}

willMoveToNextScreen 需要 BindingBoolean。我该如何解决这个问题？

Answer 1

使用Binding.constant(true)。您可以使用 Binding.constant(/*Pass your default value as per type*/) 来设置 PreviewProvider 的数据。

struct SettingsView_Previews: PreviewProvider {
    static var previews: some View {
        SettingsView(willMoveToNextScreen: .constant(true)) // Pass true or false
    }
}

SwiftUI 在预览模式下使用按钮关闭模态

SwiftUI close modal with a button in preview mode

modal-dialog

swift

swiftui