你如何在JavaFX中从一个角落到另一个角落？

Question

我想drawLine(0,0,getWidth(), getHeight())在JavaFX中做.我不只是想把数字放在我的行中.以下是JFrame和JavaFX的代码.

package project;

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class main extends JPanel{
    public static void main(String args[])
    {
        JFrame myWindow = new JFrame("Isometric Grid");
        main myPanel = new main(); //myPanel is just a name

        myWindow.setSize(400,400);
        myWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myWindow.add(myPanel);
        myWindow.setVisible(true);
    }

    //this method will override main and create a custom graphic
    public void paintComponent(Graphics myPen) //change
    {
        super.paintComponent(myPen);
        this.setBackground(Color.BLACK);  
        myPen.setColor(Color.blue);

        myPen.drawLine(0, 0, getWidth(), getHeight());
    }
}

我不想这样做:

package JavaFXApplication14;

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.stage.Stage;

public class JavaFXApplication14 extends Application {

    @Override
    public void start(Stage primaryStage) {

        Group root = new Group();

        Line ln = new Line(0,0,480,480);
        ln.setStrokeWidth(1);    
        root.getChildren().add(ln);

        Scene scene = new Scene(root, 480, 480, Color.SKYBLUE); 

        primaryStage.setTitle("Stuff");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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

}

我有的其他问题是如何做getHeight(); 在JavaFX中的for循环中:

for(int y = 0; y < getHeight(); y = y + 100)

是否有可能做这样的事情:

@Override
public void start(Stage primaryStage) {

    Group root = new Group();

    Scene scene = new Scene(root, 480, 480, Color.SKYBLUE); 
    primaryStage.setTitle("Stuff");
    primaryStage.setScene(scene);
    primaryStage.show();

    int x = (int) scene.getWidth(); 
    int y = (int) scene.getHeight(); 

    Line ln = new Line(0, 0, x, y); //480s dont matter
    ln.setStrokeWidth(1);
    root.getChildren().add(ln);

}

Answer 1

你做同样的事情,除了场景的宽度和高度.您无法使用该组,因为它会自行调整大小以包含该行.另一个技巧是绑定宽度和高度,以便您可以调整舞台大小.因此,在声明场景后,添加以下两行.

    Scene scene = new Scene(root, 480, 480, Color.SKYBLUE); 
    ln.endXProperty().bind(scene.widthProperty());
    ln.endYProperty().bind(scene.heightProperty());

如果你不想让它受到约束,那就是它 ln.setEndX(scene.getWidth());

对于矩形,

    for(int y = 0; y < scene.getHeight(); y += 20) { 
        //Rectangle(double x, double y, double width, double height)
        Rectangle rect = new Rectangle(20, y, 10, 10);
        //default is black fill but you can chamge it;
        rect.setFill(Color.RED);
        //or in css, same as this
        rect.setStyle("-fx-fill: purple;");
        //then add it to the Group
        root.getChildren().add(rect);
    }