在JavaFx实例(二)中,改变窗口的大小,绘制的圆形不会随窗口改变而改变位置,要想使圆形始终在窗口的中心,就需要用到bind()方法。用法是:target.bind(source);下面这个程序将这圆形始终保持在窗口的中心,不论怎样改变窗口大小。
import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.layout.Pane; import javafx.scene.paint.Color; import javafx.scene.shape.Circle; import javafx.stage.Stage; public class ShowCircleCentered extends Application { @Override // Override the start method in the Application class public void start(Stage primaryStage) { // Create a pane to hold the circle Pane pane = new Pane(); // Create a circle and set its properties Circle circle = new Circle(); circle.centerXProperty().bind(pane.widthProperty().divide(2)); circle.centerYProperty().bind(pane.heightProperty().divide(2)); circle.setRadius(50); circle.setStroke(Color.BLACK); circle.setFill(Color.WHITE); pane.getChildren().add(circle);// Add circle to the pane // Create a scene and place it in the stage Scene scene = new Scene(pane, 200,200); primaryStage.setTitle("ShowCircleCentered");// Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show();// Display the stage } }
运行结果如下: