JavaFX矩形不會觸及右側

Question

我在JavaFX中構建了一個矩形。我的場景的寬度爲300，我的矩形寬度爲80.

Rectangle.setX設置矩形左上角的位置。我將setX設置爲obScene.getWidth（） - carRightSide，它不會碰到右側。

我在做什麼錯？

package assign3; 

import javafx.application.Application; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.layout.FlowPane; 
import javafx.scene.layout.Pane; 
import javafx.scene.paint.Color; 
import javafx.scene.shape.Circle; 
import javafx.scene.shape.Rectangle; 
import javafx.stage.Stage; 

public class Question4 extends Application 
{ 

    public int carRightSide; 

    @Override 
    public void start(Stage obPrimeStage) throws Exception 
    { 

     Pane obPane = new Pane(); 

     Circle obWheelOne = new Circle(20, Color.BLACK); 
     obWheelOne.setRadius(20); 
     Circle obWheelTwo = new Circle(20, Color.BLACK); 
     obWheelTwo.setRadius(20); 

     Rectangle obBody = new Rectangle(80, 40, Color.LIGHTBLUE); 


     obPane.getChildren().add(obWheelOne); 
     obPane.getChildren().add(obBody); 

     Scene obScene = new Scene(obPane, 300, 350); 

     carRightSide = 80; 
     obBody.setX(obScene.getWidth() - carRightSide); 
     obBody.setY(40); 

     obPrimeStage.setTitle("Driving Cars"); 
     obPrimeStage.setScene(obScene); 
     obPrimeStage.setResizable(false); 
     obPrimeStage.show(); 


    } 

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

    } 

} 

Answer 1

你必須調用obPrimeStage.show();使用Scene的.getWidth()之前。

public class Question4 extends Application 
{ 

    public int carRightSide = 80; 

    @Override 
    public void start(Stage obPrimeStage) throws Exception 
    { 

     Pane obPane = new Pane();   

     Scene obScene = new Scene(obPane, 300, 350, Color.ANTIQUEWHITE); 
     obPrimeStage.setScene(obScene);//Add scene here 
     obPrimeStage.setTitle("Driving Cars"); 
     obPrimeStage.setResizable(false); 
     obPrimeStage.show();//Show Stage so that the size will be calculated 

     Circle obWheelOne = new Circle(20, Color.BLACK); 
     obWheelOne.setRadius(20); 
     Circle obWheelTwo = new Circle(20, Color.BLACK); 
     obWheelTwo.setRadius(20); 

     Rectangle obBody = new Rectangle(carRightSide, 40, Color.LIGHTBLUE); 
     obBody.setX(obScene.getWidth() - carRightSide); 
     obBody.setY(40); 

     obPane.getChildren().add(obBody); 
     obPane.getChildren().add(obWheelOne); 
     obPane.getChildren().add(obWheelTwo); 
    } 

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

，或者你可以設置Scene

Scene obScene = new Scene(obPane, 300, 350, Color.ANTIQUEWHITE); 
obPrimeStage.setScene(obScene);//Add scene here 
obPrimeStage.setWidth(obScene.getWidth()); 
obPrimeStage.setHeight(obScene.getHeight()); 

//Circles 
//Rectangle 
//Adding components 
obPrimeStage.setTitle("Driving Cars"); 
obPrimeStage.setResizable(false); 
obPrimeStage.show();//Show Stage so that the size will be calculated