testcanvas.java

来自「提供了常用的JAVA技术的示例」· Java 代码 · 共 38 行

package TestCanvas;

import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class TestCanvas extends Canvas implements KeyListener{
    String s="";
    public void paint(Graphics g){
        g.setColor(Color.magenta);
        g.drawRect(50,50,100,100);
        g.drawString("你好吗？",60,60);
    }
    public void keyReleased(KeyEvent e){
        System.out.println("keyReleased");
    }
    public void keyTyped(KeyEvent ev){
        requestFocus();
        s+=ev.getKeyChar();
        getGraphics().drawString(s,30,20);
    }
    public void keyPressed(KeyEvent ev){
        System.out.println("keypressed");
    }

    public static void main(String[] args) {
        TestCanvas c = new TestCanvas();
        Frame f=new Frame("testing canvas");
        c.addKeyListener(c);
        f.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){System.exit(0);}
            });
        f.setLayout(new BorderLayout());
        f.add(c,"Center");
        f.setSize(200,200);
        f.setVisible(true);
      }
}