Paint方法java - 带轮廓的Rectangle

Question

我想创建一个蓝色线条轮廓和黑色填充的墙.我现在只有一个蓝色的墙,我尝试了几个图形方法,但没有工作.

public void paint(Graphics g) {
    g.setColor(Color.blue);
    g.fillRect(x, y, size, size);
}

Answer 1

使用Graphics#drawRect绘制轮廓: -

g.setColor(Color.black);
g.fillRect(x, y, size, size);
g.setColor(Color.blue);
g.drawRect(x, y, size, size);

Answer 2

首先,覆盖paintComponent,而不是paint.其次,没有必要像这样重新发明轮子.相反,使用现有的Swing组件(例如JPanel),

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class Main 
{
    public static void main(String[] args) 
    {        
        SwingUtilities.invokeLater(new Runnable(){
            @Override
            public void run() {
                createAndShowGUI();             
            }
        });
    }

    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new FlowLayout());
        frame.add(getWallComponent());
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private static JPanel getWallComponent()
    {
        JPanel panel = new JPanel();

        panel.setBackground(Color.black);
        panel.setBorder(BorderFactory.createLineBorder(Color.blue, 5));
        panel.setPreferredSize(new Dimension(200, 200)); // for demo purposes only

        return panel;
    }
}