J2ME Form跳转

MainMidlet.java

 

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class MainMidlet extends MIDlet implements CommandListener
{
    private Display display;
    private Form form = new Form("Wellcome!!");
    private Command okCommand = new Command("OK",Command.OK,1);//选择OK,换到下一个屏幕
    private Form ns ;
    private StringItem si = new StringItem("First Screen","~_~");
    public MainMidlet()
    {
        form.addCommand(okCommand);
        form.append(si);
    }
    public void startApp() {
        display = Display.getDisplay(this);
        display.setCurrent(form);
        form.setCommandListener(this);
    }
    public void pauseApp()
    {

    }
    public void destroyApp(boolean b)
    {

    }
    public void commandAction(Command c,Displayable s)
    {
        if(c==okCommand)
        {
            ns = new NextScreen(display,form);//最关键的地方在这里：)
            display.setCurrent(ns);
        }
    }
}

 

NextScreen.java

 

import javax.microedition.lcdui.*;

public class NextScreen extends Form implements CommandListener
{
    private Display display;
    private Displayable parent;
    private Command backCommand = new Command("BACK",Command.BACK,1);
    private StringItem si = new StringItem("SecondScrean","~_~");
    public NextScreen(Display d,Displayable p)
    {
        super("nextscreen");//使得NextScreen可以直接调中其父类Form中的函数
        display = d;
        parent = p;
        append(si);
        addCommand(backCommand);
        setCommandListener(this);
    }
    public void commandAction(Command c,Displayable s)
    {
        if(c==backCommand)
        {
        display.setCurrent(parent);
        }
    }
}