swiftui - 通过实时预览 (SwiftUI) 执行操作/使用手势

Question

我有 CustomToggle，我想通过实时预览 对其进行测试。问题在于，通过实时预览点击切换不会执行任何操作，但在运行模拟器时效果很好。

struct CustomToggle: View {
    @Binding var isOn: Bool

    // ... displaying CustomToggle view
    // ... and toggling isON onTapGesture

}

struct CustomToggle_Previews: PreviewProvider {
    @State static var isOn = true
    static var previews: some View {
        CustomToggle(isOn: $isOn)
    }
}

Answer 1

您可以为此目的定义一个结构:

struct StatefulPreviewWrapper<Value, Content: View>: View {
    @State var value: Value
    var content: (Binding<Value>) -> Content

    var body: some View {
        content($value)
    }

    init(_ value: Value, content: @escaping (Binding<Value>) -> Content) {
        self._value = State(wrappedValue: value)
        self.content = content
    }
}

然后在预览中使用它，如下所示:

struct CustomToggle_Previews: PreviewProvider {
    static var previews: some View {
        StatefulPreviewWrapper(false) { CustomToggle(isOn: $0) }
    }
}