keycodecanvas.java

这是j2me的例子,可供初学者学习,里面有源代码,是我写的

/*
 * KeyCodeCanvas.java
 *
 * Created on 2007年3月28日, 下午12:51
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package com.tan.ui.key;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;

/**
 *
 * @author USER
 */
public class KeyCodeCanvas extends Canvas implements CommandListener{
    private Command cmExit;
    private String keyText = null;
    private KeyCodes midlet;
    /** Creates a new instance of KeyCodeCanvas */
    public KeyCodeCanvas(KeyCodes midlet) {
        this.midlet = midlet;
        cmExit = new Command("Exit",Command.EXIT,1);
        addCommand(cmExit);
        setCommandListener(this);
    }
    
    protected void paint(Graphics graphics) {
        graphics.setColor(255,255,255);
        graphics.fillRect(0,0,getWidth(),getHeight());
        if(keyText != null)
        {
            graphics.setColor(0,0,0);
            graphics.drawString(keyText,getWidth()/2,getHeight()/2,Graphics.TOP|Graphics.HCENTER);
        }
    }
    
    public void commandAction(Command command, Displayable displayable) {
        if(command == cmExit)
            midlet.exitMIDlet();
    }
    
    public void keyPressed(int keyCode)
    {
        keyText = getKeyName(keyCode);
        repaint();
    }
}