新建 文本文档.txt

来自「java编辑的一个小型应用程序可以用来进行基本的绘图」· 文本 代码 · 共 59 行

import java.awt.*;       // Java core packages
import java.awt.event.*; // Java core packages
import javax.swing.*;    // Java extension packages

public class J_Draw extends JFrame
{
    int     m_x= 0,  m_y= 0;
    int     m_oldX= 0,  m_oldY= 0;

    public J_Draw()
    {
        super("Example of mouse event handling");

addMouseListener( new MouseAdapter()
            {
                public void mousePressed(MouseEvent e)
                {
                    m_x= e.getX();
                    m_y= e.getY();
                    m_oldX= m_x;
                    m_oldY= m_y;
                    repaint();
                } // End of method: mousePressed
            } // End of the anonymous inner class,
              // which implements MouseAdapter
        ); // End of invoking addMouseAdapter
addMouseMotionListener( new MouseMotionAdapter()
            {
                public void mouseDragged(MouseEvent e) 
                {
                    m_oldX= m_x;
                    m_oldY= m_y;
                    m_x= e.getX();
                    m_y= e.getY();
                    repaint();
                } // End of method: mouseDragged
            } // End of the anonymous inner class, 
              // which implements MouseMotionAdapter
        ); // End of invoking addMouseMotionAdapter
        
        setSize(250, 150);
        setVisible(true);
    } // End of constructor: J_Draw

public void paint(Graphics g)
    {
        g.drawLine(m_oldX, m_oldY, m_x, m_y);
    } // End of method: paint

    public static void main( String args[] )
    { 
        JFrame app = new J_Draw( );

        Container cp = app.getContentPane();
        app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
    } // End of method: main

} // End of class: J_Draw