Question

我想用Java做一个非常简单的“Paint”。现在我遇到了麻烦，因为我不知道如何使用JRaddioButtons中的actionListener来更改我想要绘制的线条的颜色。

我显示我的代码，抱歉，如果太大：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Line2D;
import java.util.ArrayList;
import javax.swing.JComponent;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.JPanel;
import javax.swing.JFrame;



public class Dibujar extends JComponent {

    private Point inicioArrastre;
    private Point finArrastre;
    private ArrayList<Shape> lineas = new ArrayList<Shape>();


    public Dibujar() {
        super();
        addMouseListener(new MouseAdapter() {

            public void mousePressed(MouseEvent e) { // cuando se presiona el mouse
                inicioArrastre = new Point(e.getX(), e.getY());
                repaint();
            }

            public void mouseReleased(MouseEvent e) { // cuando se deja de presionar el mouse
                finArrastre = new Point(e.getX(), e.getY());
                Shape linea = crearLinea(inicioArrastre.x, inicioArrastre.y, finArrastre.x, finArrastre.y);
                lineas.add(linea);
                repaint();
            }
        });
        addMouseMotionListener(new MouseMotionAdapter() {

            public void mouseDragged(MouseEvent e) { // cuando se esta arrastrando el mouse
                finArrastre = new Point(e.getX(), e.getY());
                Shape linea = crearLinea(inicioArrastre.x, inicioArrastre.y, finArrastre.x, finArrastre.y);
                lineas.add(linea);
                inicioArrastre = new Point(finArrastre.x, finArrastre.y);
                repaint();
            }
        });
    }

    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        g2.setColor(Color.RED);
        for (Shape linea : lineas) { // dibuja todos las elipses
            g2.draw(linea);
        }
    }

    private Line2D.Float crearLinea(int x1, int y1, int x2, int y2) {
        return new Line2D.Float(x1, y1, x2, y2);
    }

    public static void main(String[] a3d) {
        Dibujar dibu = new Dibujar();
        JFrame ventana = new JFrame("Dibujar");
        ventana.setJMenuBar(dibu.createMenuBar());
        ventana.setSize(400, 300);
        ventana.setLocationRelativeTo(null);
        ventana.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        ventana.add(new Dibujar());
        ventana.setVisible(true);
    }


    public JMenuBar createMenuBar() {
        JMenuBar menuBar;
        JMenu menu, submenu;
        JMenuItem menuItem;
        JRadioButtonMenuItem rbMenuItem;

        //Create the menu bar.
        menuBar = new JMenuBar();

        //Build the first menu.
        menu = new JMenu("A Menu");
        menu.setMnemonic(KeyEvent.VK_A);
        menu.getAccessibleContext().setAccessibleDescription(
                "The only menu in this program that has menu items");
        menuBar.add(menu);

        //a group of JMenuItems
        menuItem = new JMenuItem("Select a Color",
                                 KeyEvent.VK_T);
        //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead
        menuItem.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_1, ActionEvent.ALT_MASK));
        menuItem.getAccessibleContext().setAccessibleDescription(
                "This doesn't really do anything");
        menu.add(menuItem);


        menuItem.setMnemonic(KeyEvent.VK_B);
        menu.add(menuItem);


        menuItem.setMnemonic(KeyEvent.VK_D);
        menu.add(menuItem);

        //a group of radio button menu items
        menu.addSeparator();
        ButtonGroup group = new ButtonGroup();

        rbMenuItem = new JRadioButtonMenuItem("RED");
        rbMenuItem.setSelected(true);
        rbMenuItem.setMnemonic(KeyEvent.VK_R);
        rbMenuItem.addActionListener(null);
        group.add(rbMenuItem);
        menu.add(rbMenuItem);

        rbMenuItem = new JRadioButtonMenuItem("BLUE");
        rbMenuItem.setMnemonic(KeyEvent.VK_B);
        group.add(rbMenuItem);
        menu.add(rbMenuItem);



        return menuBar;
    }
    }

非常感谢你！

Answer 1

您只需要一个actionperformed方法

 RadioButton.addActionListener(new ActionListener() 
{
  public void actionPerformed(ActionEvent e) 
  {
    // Enter your code, to change the color    
  }
});

如何在JRadioButtons中使用ActionListener

1 个答案: