在JavaFX中显示字符串/标签

Question

我需要帮助弄清楚如何在程序中显示文本，以便它可以在我创建的多边形形状的中间显示“停止”。我想做的是创建一个停车标志。我已经负责创建和显示该停车标志，因此现在只需要在屏幕上显示“停止”即可

package application;
public class Main extends Application {
@Override
public void start(Stage primaryStage) {
    Pane pane = new Pane();
    Polygon polygon = new Polygon();
    pane.getChildren().add(polygon);
    polygon.setFill(javafx.scene.paint.Color.RED); //sets the color of polygon
    ObservableList<Double> list = polygon.getPoints();

    //create a label to display in the middle of the "stop sign" polygon shape
    //This is what I need most help on
    Label sign = new Label("Stop"); 
    sign.setAlignment(Pos.CENTER);
    System.out.print(sign);

    final double WIDTH = 200, HEIGHT = 200;
    double centerX = WIDTH / 2, centerY = HEIGHT / 2;
    double radius = Math.min(WIDTH, HEIGHT) * 0.4;

    // Add points to the polygon list
    for (int i = 0; i < 6; i++){
        list.add(centerX + radius * Math.cos(2 * i * Math.PI / 6));
        list.add(centerY - radius * Math.sin(2 * i * Math.PI / 6));
    }

    // Create a scene and place it in the stage
    Scene scene = new Scene(pane, WIDTH, HEIGHT);
    primaryStage.setTitle("ShowPolygon"); //Set the stage title 
    primaryStage.setScene(scene); //Place the scene in the stage
    primaryStage.show(); //Display the stage



}

public static void main(String[] args) {
    launch(args);
}

}

Answer 1

更换Pane用StackPane，并添加sign到它（多边形后）：

public void start(Stage primaryStage) {
    StackPane pane = new StackPane();
    Polygon polygon = new Polygon();
    polygon.setFill(javafx.scene.paint.Color.RED); //sets the color of polygon
    ObservableList<Double> list = polygon.getPoints();

    //create a label to display in the middle of the "stop sign" polygon shape
    //This is what I need most help on
    Label sign = new Label("STOP");
    //sign.setStyle("-fx-text-fill: white; -fx-font-size: 3em");
    sign.setAlignment(Pos.CENTER);
    System.out.print(sign);


    pane.getChildren().add(polygon);
    pane.getChildren().add(sign);

    final double WIDTH = 200, HEIGHT = 200;
    double centerX = WIDTH / 2, centerY = HEIGHT / 2;
    double radius = Math.min(WIDTH, HEIGHT) * 0.4;

    // Add points to the polygon list
    for (int i = 0; i < 6; i++) {
        list.add(centerX + radius * Math.cos(2 * i * Math.PI / 6));
        list.add(centerY - radius * Math.sin(2 * i * Math.PI / 6));
    }

    // Create a scene and place it in the stage
    Scene scene = new Scene(pane, WIDTH, HEIGHT);
    primaryStage.setTitle("ShowPolygon"); //Set the stage title
    primaryStage.setScene(scene); //Place the scene in the stage
    primaryStage.show(); //Display the stage


}

关于的Javadoc StackPane：

StackPane将其子级放在从后到前的堆栈中。子级的z顺序由子级列表的顺序定义，第0个子级是底部，最后一个子级在顶部。如果已设置边框和/或填充，则将在这些插图内布置孩子。

堆栈窗格将尝试调整每个子项的大小以填充其内容区域。如果无法调整子级的大小来填充堆栈窗格（因为无法调整大小或最大尺寸阻止了它），那么它将使用alignment属性（默认值为Pos.CENTER）在区域内对其进行对齐。