Question

我正在使用Kotlin和TornadoFX编写PC应用程序。

我会告诉你我拥有的东西

FooModel.kt：

class FooModel(val id: Int){
    constructor(foo: Foo) : this(foo.id)
}

Foo.kt：

data class Foo(val id: Int)

MainController.kt：

val FoosList: ObservableList<FooModel> = FXCollections.observableArrayList<FooModel>()

//bellow I wanna describe what I’m already doing with val above

fun fooDifferentOperationsForExample(example: Int){
    example1Object = FoosList.find{ it.id == example }
    example2Object.removeIf { it.id == example }
    example3Object.setAll(it.map {FooModel})
}

我正在列表视图中显示model的描述，并希望在同一列表中添加其他类型的对象。我有一个sealed class的解决方案，例如DifferentKindsOfInstances.kt的示例：

sealed class DifferentKindsOfInstances{
    data class Foo(val foo: FooModel): DiffrentKindsOfInstances()
    data class Bar(val bar: BarModel): DiffrentKindsOfInstances()
}

让我们以为BarModel是FooModel的精确副本，没关系。

但是，如果我想以以前的工作方式（在MainControl中）继续使用FooModel，那么代码将如何显示？

it.foo.id对我不起作用

Answer 1

这是在两个地方引用密封类成员的解决方案：在cellFragment {}中渲染ListCell以及将所选密封类项目绑定到文本字段字符串内容。

class ItemModel1 ( val dataField1 : String )
class ItemModel2 ( val dataField2 : String )

sealed class ItemViewInstance {
    data class Item1(val item1: ItemModel1): ItemViewInstance()
    data class Item2(val item2: ItemModel2): ItemViewInstance()
}

class SealedClassDemoView : View("Sealed Class") {

    val instances = listOf(
            ItemViewInstance.Item1(ItemModel1("One")),
            ItemViewInstance.Item2(ItemModel2("Two"))
    ).observable()

    val selectedItemString = SimpleStringProperty()

    override val root = vbox {
        listview(instances) {
            cellFormat {
                when( it ) {
                    is ItemViewInstance.Item1 -> text = it.item1.dataField1
                    is ItemViewInstance.Item2 -> text = it.item2.dataField2
                }
            }

            selectedItemString.bind(
                    Bindings.createStringBinding(
                        Callable  {
                            val sel = selectionModel.selectedItemProperty().value
                            when (sel) {
                                is ItemViewInstance.Item1 -> sel.item1.dataField1
                                is ItemViewInstance.Item2 -> sel.item2.dataField2
                                else -> ""
                            }
                        },
                        selectionModel.selectedItemProperty()
                    )
            )
        }
        textfield(selectedItemString)
        padding = Insets(2.0)
        spacing = 4.0
    }
}

class SealedClassDemoApp : App(SealedClassDemoView::class)

fun main(args: Array<String>) {
    launch<SealedClassDemoApp>(args)
}

将不同的模型合并为密封类

1 个答案: