commandactionhandle.java

用Eclipse开发J2me书籍的程序源码。

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class CommandActionHandle extends MIDlet implements CommandListener {
    Display display;
    Form frmMain = new Form("命令按钮事件处理演示");
    
    //命令按钮
    Command cmdScreen1 = new Command("SCREEN1", Command.SCREEN, 1);
    Command cmdScreen2 = new Command("SCREEN2", Command.SCREEN, 2);
    Command cmdScreen3 = new Command("SCREEN3", Command.SCREEN, 3);
    
    Command cmdExit1 = new Command("退出", Command.EXIT, 1);
    
    public CommandActionHandle() {
        super();
        // TODO Auto-generated constructor stub
    }

    protected void startApp() throws MIDletStateChangeException {
        display = Display.getDisplay(this);
        frmMain.addCommand(cmdScreen3);
        frmMain.addCommand(cmdScreen2);
        frmMain.addCommand(cmdScreen1);
        
        frmMain.addCommand(cmdExit1);
        frmMain.setCommandListener(this);
        
        display.setCurrent(frmMain);

    }

    protected void pauseApp() {
        // TODO Auto-generated method stub

    }

    protected void destroyApp(boolean arg0) 
        throws MIDletStateChangeException {
        // TODO Auto-generated method stub

    }

    //处理命令按钮事件
    public void commandAction(Command c, Displayable d) {
        if (c == cmdExit1) {
            notifyDestroyed();
        } else {
            frmMain.append(c.getLabel()+ "按钮被按下\n");
        }
        
        //另外一种处理方式
        String s = c.getLabel();
        if (s.equals("退出")) {
            notifyDestroyed();
        } else {
            frmMain.append(s+ "按钮被按下\n");
        }
    }
}