imageitemdemo.java

图书中的经典例子 好好看看 会有帮助的。java2me版本的

//imageItemDemo.java file
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import itemex.*;

public class imageItemDemo extends MIDlet implements CommandListener, ItemCommandListener 
{
    private Command exitCommand, aCommand1, aCommand2, aCommand3;
    private Form form;
    ImageItem imageLogo,imageAlt;
    ButtonImage buttonPlay;
    HyperLinkImage linkCode;
    
    public imageItemDemo()
    {
        exitCommand =new Command("Exit",Command.EXIT,1);
        aCommand1 =new Command("ImageLogo",Command.SCREEN,2);
        aCommand2 =new Command("Button",Command.SCREEN,2);
        aCommand3 =new Command("HyperLink",Command.SCREEN,2);
        form = new Form("ImageItem form");
        form.addCommand(exitCommand);
        form.addCommand(aCommand1);
        form.addCommand(aCommand2);
        form.addCommand(aCommand3);

        form.setCommandListener(this);
        try
        {//程序创建时添加PLAIN 模式的图像
            imageLogo = new ImageItem("logo.png", Image.createImage("/logo.png"),
                                        Item.LAYOUT_DEFAULT ,
                                        "large.png");
            form.append(imageLogo);
        }
        catch(Exception e) { System.out.println("load image error");}
    }
    protected void startApp(  ) throws MIDletStateChangeException
    {
        Display.getDisplay(this).setCurrent(form);
    }

    protected void pauseApp(  )
    {
    }

    protected void destroyApp( boolean p1 )
    {
    }

    public void commandAction(Command c,Displayable d)
    {
        if (c ==exitCommand)
        {
            destroyApp(false);
            notifyDestroyed();
        }
        else if (c ==aCommand1)
        {//切换到imageLogo
            if(form.get(0) != imageLogo)
            {//检查当前显示，如果imageLogo没有被显示才执行操作
                form.delete(0);
                form.append(imageLogo);
            }
        }
        else if (c ==aCommand2)
        {//切换到buttonPlay
            if(buttonPlay == null)
            {//第一次使用时才创建对象
                try
                {
                    buttonPlay = new ButtonImage("Play Sound", Image.createImage("/announce.png"),
                                                Item.LAYOUT_EXPAND|Item.LAYOUT_NEWLINE_AFTER|Item.LAYOUT_2 ,
                                                "announce.png", this);
                }
                catch(Exception e) { System.out.println("load image error");}
            }
            if(form.get(0) != buttonPlay)
            {//检查当前显示，如果buttonPlay没有被显示才执行操作
                form.delete(0);
                form.append(buttonPlay);
            }
        }
        else if (c ==aCommand3)
        {//切换到linkCode
            if(linkCode == null)
            {//第一次使用时才创建对象
                try
                {
                    linkCode = new HyperLinkImage("http://wyy.vchelp.net/book/jmcode.zip", 
                                                Image.createImage("/download.png"),
                                                Item.LAYOUT_EXPAND|Item.LAYOUT_NEWLINE_AFTER|Item.LAYOUT_2,
                                                "download.png", this);
                }
                catch(Exception e) { System.out.println("load image error");}
            }
            if(form.get(0) != linkCode)
            {//检查当前显示，如果linkCode没有被显示才执行操作
                form.delete(0);
                form.append(linkCode);
            }
        }
    }

    public void commandAction(Command c,Item i)
    {
        if(i == linkCode)
        {//处理来自HyperLink的命令
            System.out.println("goto "+ i.getLabel());
        }
        else if(i == buttonPlay)
        {//处理来自Button的命令
            System.out.println("Command "+ i.getLabel());
        }
    }
}