JavaFX基础与图形处理实战

# JavaFX 基础与图形处理实战 ## 1. JavaFX TabPane 控件使用 ### 1.1 TabPane 简介 TabPane 控件用于创建选项卡界面，它与 Java Swing 的 JTabbedPanel 类似，但使用方式有所不同。在 TabPane 中，我们添加的是 `javafx.scene.control.Tab` 实例，而非 JPanels。 ### 1.2 设置 Tab 方向 可以通过菜单选项来设置 Tab 的方向，包括左、右、上、下。以下是设置 Tab 方向的代码示例： ```java public void handle(ActionEvent event) { MenuItem mItem = (MenuItem) event.getSource(); String side = mItem.getText(); if ("left".equalsIgnoreCase(side)) { tabPane.setSide(Side.LEFT); } else if ("right".equalsIgnoreCase(side)) { tabPane.setSide(Side.RIGHT); } else if ("top".equalsIgnoreCase(side)) { tabPane.setSide(Side.TOP); } else if ("bottom".equalsIgnoreCase(side)) { tabPane.setSide(Side.BOTTOM); } } ``` ### 1.3 添加 Tab 到 TabPane 以下代码展示了如何将 Tab 添加到 TabPane 中： ```java TabPane tabPane = new TabPane(); Tab tab = new Tab(); tab.setText("Tab" + i); tabPane.getTabs().add(tab); ``` ## 2. 开发 JavaFX 对话框 ### 2.1 问题描述 需要创建一个模拟更改密码的对话框应用程序，该应用包含菜单选项以弹出对话框，并且用户可以设置对话框的模态状态。 ### 2.2 解决方案 使用 JavaFX 的 `javafx.stage.Stage` 和 `javafx.scene.Scene` API 来创建对话框。以下是完整的代码示例： ```java import javafx.application.Application; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.*; import javafx.scene.input.KeyCode; import javafx.scene.input.KeyCodeCombination; import javafx.scene.input.KeyCombination; import javafx.scene.paint.Color; import javafx.stage.Modality; import javafx.stage.Stage; import javafx.animation.Animation; import javafx.animation.KeyFrame; import javafx.animation.Timeline; import javafx.util.Duration; import javafx.scene.shape.Circle; import javafx.scene.paint.RadialGradient; import javafx.scene.paint.Stop; import javafx.scene.paint.CycleMethod; import javafx.scene.layout.GridPane; import javafx.geometry.Insets; import javafx.geometry.HPos; import javafx.stage.Platform; public class DevelopingADialog extends Application { static Stage LOGIN_DIALOG; static int dx = 1; static int dy = 1; public static void main(String[] args) { Application.launch(args); } private static Stage createLoginDialog(Stage parent, boolean modal) { if (LOGIN_DIALOG != null) { LOGIN_DIALOG.close(); } return new MyDialog(parent, modal, "Welcome to JavaFX!"); } @Override public void start(final Stage primaryStage) { primaryStage.setTitle("Developing a Dialog"); Group root = new Group(); Scene scene = new Scene(root, 433, 312, Color.WHITE); MenuBar menuBar = new MenuBar(); menuBar.prefWidthProperty().bind(primaryStage.widthProperty()); Menu menu = new Menu("Home"); MenuItem newItem = new MenuItem("Change Password", null); newItem.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { if (LOGIN_DIALOG == null) { LOGIN_DIALOG = createLoginDialog(primaryStage, true); } LOGIN_DIALOG.sizeToScene(); LOGIN_DIALOG.show(); } }); menu.getItems().add(newItem); menu.getItems().add(new SeparatorMenuItem()); ToggleGroup modalGroup = new ToggleGroup(); RadioMenuItem nonModalItem = RadioMenuItemBuilder.create() .toggleGroup(modalGroup) .text("Non Modal") .selected(true) .build(); nonModalItem.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { LOGIN_DIALOG = createLoginDialog(primaryStage, false); } }); menu.getItems().add(nonModalItem); RadioMenuItem modalItem = RadioMenuItemBuilder.create() .toggleGroup(modalGroup) .text("Modal") .selected(true) .build(); modalItem.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { LOGIN_DIALOG = createLoginDialog(primaryStage, true); } }); menu.getItems().add(modalItem); menu.getItems().add(new SeparatorMenuItem()); MenuItem exitItem = new MenuItem("Exit", null); exitItem.setMnemonicParsing(true); exitItem.setAccelerator(new KeyCodeCombination(KeyCode.X, KeyCombination.CONTROL_DOWN)); exitItem.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { Platform.exit(); } }); menu.getItems().add(exitItem); menuBar.getMenus().add(menu); root.getChildren().add(menuBar); primaryStage.setScene(scene); primaryStage.show(); addBouncyBall(scene); } private void addBouncyBall(final Scene scene) { final Circle ball = new Circle(100, 100, 20); RadialGradient gradient1 = new RadialGradient(0, .1, 100, 100, 20, false, CycleMethod.NO_CYCLE, new Stop(0, Color.RED), new Stop(1, Color.BLACK)); ball.setFill(gradient1); final Group root = (Group) scene.getRoot(); root.getChildren().add(ball); Timeline tl = new Timeline(); tl.setCycleCount(Animation.INDEFINITE); KeyFrame moveBall = new KeyFrame(Duration.seconds(.0200), new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { double xMin = ball.getBoundsInParent().getMinX(); double yMin = ball.getBoundsInParent().getMinY(); double xMax = ball.getBoundsInParent().getMaxX(); double yMax = ball.getBoundsInParent().getMaxY(); if (xMin < 0 || xMax > scene.getWidth()) { dx = dx * -1; } if (yMin < 0 || yMax > scene.getHeight()) { dy = dy * -1; } ball.setTranslateX(ball.getTranslateX() + dx); ball.setTranslateY(ball.getTranslateY() + dy); } }); tl.getKeyFrames().add(moveBall); tl.play(); } } class MyDialog extends Stage { public MyDialog(Stage owner, boolean modality, String title) { super(); initOwner(owner); Modality m = modality ? Modality.APPLICATION_MODAL : Modality.NONE; ```