从Java到Kotlin
我正在努力将用Java编写的简单的JavaFX calc转换成Kotlin代码。 https://gist.github.com/jewelsea/4344564 – > java源码。
我在Kotlin翻译的是：
import Model.Math import javafx.application.Application import javafx.beans.binding.Bindings import javafx.beans.property.* import javafx.event.ActionEvent import javafx.event.EventHandler import javafx.geometry.Pos import javafx.scene.Scene import javafx.scene.control.* import javafx.scene.input.KeyEvent import javafx.scene.layout.* import javafx.stage.Stage import javafx.stage.StageStyle import java.util.HashMap // A simple Kotlin, JavaFX application class KotlinCode : Application() { private val accelerators = HashMap<String, Button>() private val stackValue = SimpleDoubleProperty() private val value = SimpleDoubleProperty() enum class Op { NOOP, ADD, SUBTRACT, MULTIPLY, DIVIDE } private var curOp = Op.NOOP private var stackOp = Op.NOOP private val template = arrayOf(arrayOf("7", "8", "9", "/"), arrayOf("4", "5", "6", "*"), arrayOf("1", "2", "3", "-"), arrayOf("0", "c", "=", "+")) override fun start(stage: Stage) { val screen = createScreen() val buttons = createButtons() stage.title = "Calc" stage.initStyle(StageStyle.UTILITY) stage.isResizable = false stage.scene = Scene(createLayout(screen, buttons)) stage.show() } private fun createLayout(screen: TextField, buttons: TilePane): VBox { val layout = VBox(20.0) layout.alignment = Pos.CENTER layout.style = "-fx-background-color: chocolate; -fx-padding: 20; -fx-font-size: 20;" layout.children.setAll(screen, buttons) handleAccelerators(layout) screen.prefWidthProperty().bind(buttons.widthProperty()) return layout } private fun handleAccelerators(layout: VBox) { layout.addEventFilter(KeyEvent.KEY_PRESSED) { keyEvent -> val activated = accelerators[keyEvent.text] activated?.fire() } } private fun createScreen(): TextField { val screen = TextField() screen.style = "-fx-background-color: aquamarine;" screen.alignment = Pos.CENTER_RIGHT screen.isEditable = false screen.textProperty().bind(Bindings.format("%.0f", value)) return screen } private fun createButtons(): TilePane { val buttons = TilePane() buttons.vgap = 7.0 buttons.hgap = 7.0 buttons.prefColumns = template[0].size for (r in template) { for (s in r) { buttons.children.add(createButton(s)) } } return buttons } private fun createButton(s: String): Button { val button = makeStandardButton(s) if (s.matches("[0-9]".toRegex())) { makeNumericButton(s, button) //this.javaCode.makeNumericButton(s, button, curOp, value, stackValue, stackOp) } else { val triggerOp = determineOperand(s) if (triggerOp.get() != Op.NOOP) { //this.javaCode.makeOperandButton(button, triggerOp, this.curOp) makeOperandButton(button, triggerOp) } else if ("c" == s) { //this.javaCode.makeClearButton(button, value) makeClearButton(button) } else if ("=" == s) { makeEqualsButton(button) } } return button } private fun determineOperand(s: String): ObjectProperty<Op> { val triggerOp = SimpleObjectProperty(Op.NOOP) when (s) { "+" -> triggerOp.set(Op.ADD) "-" -> triggerOp.set(Op.SUBTRACT) "*" -> triggerOp.set(Op.MULTIPLY) "/" -> triggerOp.set(Op.DIVIDE) } return triggerOp } private fun makeStandardButton(s: String): Button { val button = Button(s) button.style = "-fx-base: beige;" accelerators.put(s, button) button.setMaxSize(java.lang.Double.MAX_VALUE, java.lang.Double.MAX_VALUE) return button } private fun makeEqualsButton(button: Button) { button.style = "-fx-base: ghostwhite;" button.setOnAction { actionEvent -> // On instancie notre objet Kotlin val math = Math() when (stackOp) { Op.NOOP -> { } Op.ADD -> value.set(math.adition(stackValue.get(), value.get())) Op.SUBTRACT -> value.set(math.substraction(stackValue.get(), value.get())) Op.MULTIPLY -> value.set(math.multiplication(stackValue.get(), value.get())) Op.DIVIDE -> value.set(math.division(stackValue.get(), value.get())) } } } private fun makeOperandButton(button: Button, triggerOp: ObjectProperty<Op>) { button.onAction = EventHandler { fun handle(actionEvent: ActionEvent) { curOp = triggerOp.get() } } } private fun makeNumericButton(s: String, button: Button) { button.onAction = EventHandler { fun handle(actionEvent: ActionEvent) { if (curOp == Op.NOOP) { value.set(value.get() * 10 + Integer.parseInt(s)) } else { stackValue.set(value.get()) value.set(java.lang.Double.parseDouble(s)) stackOp = curOp curOp = Op.NOOP } } } } private fun makeClearButton(button: Button) { button.onAction = EventHandler { fun handle(actionEvent: ActionEvent) { value.set(0.0) } } } companion object { @JvmStatic fun main(args: Array<String>) { launch(KotlinCode::class.java) } } } 现在计算开始，但没有绑定到按钮的动作。 任何人都有线索？
我的猜测是，在makeOperandButton中 ， makeNumericButton和makeClearButton的句柄函数从不触发。 但我不明白为什么。
非常感谢，祝你有美好的一天！
好吧，其实这很简单，我不能猜测。 我可以直接在EventHandler中运行代码。 现在一切正常！
3种方法应该是这样的：
private fun makeOperandButton(button: Button, triggerOp: ObjectProperty<Op>) { button.onAction = EventHandler { curOp = triggerOp.get() } } private fun makeNumericButton(s: String, button: Button) { button.onAction = EventHandler { if (curOp == Op.NOOP) { value.set(value.get() * 10 + Integer.parseInt(s)) } else { stackValue.set(value.get()) value.set(java.lang.Double.parseDouble(s)) stackOp = curOp curOp = Op.NOOP } } } private fun makeClearButton(button: Button) { button.onAction = EventHandler { value.set(0.0) } }