maincanvas.java

<j2me 开发精解> 詹建光著 里所有的源码。对J2me的开发相当有帮助

package com.j2medev.chapter4;

import javax.microedition.lcdui.*;

public class MainCanvas extends Canvas implements CommandListener{
    
    private RMSMIDlet midlet = null;
    private Database database = new Database();
    public static final Command exitCommand = new Command("退出",Command.EXIT,1);
    
    public MainCanvas(RMSMIDlet midlet) {
         this.midlet = midlet;
         this.addCommand(exitCommand);
         this.setCommandListener(this);
    }
    
    public void paint(Graphics g){
        //使用白色绘制整个屏幕
        int color = g.getColor();
        g.setColor(0xFFFFFF);
        g.fillRect(0,0, getWidth(),getHeight());
        g.setColor(color);
        //从RecordStore中读取图片
        Image img = database.getImage();
        if(img != null){
            g.drawImage(img, getWidth()/4,getHeight()/4, Graphics.LEFT|Graphics.TOP);
        }
        //从RecordStore中读取文字信息
        String text = database.getText();
        if(text != null){
            g.drawString(text,getWidth()/4,img.getHeight()+getHeight()/4,Graphics.LEFT|Graphics.TOP);
        }
    }

    public void commandAction(Command cmd,Displayable displayable){
        if(cmd == exitCommand){
            midlet.exit();
        }
    } 
}