fewcommandsmidlet.java

Java移动通信程序设计-J2MEMIDPJavaydccsj-J2MEMIDP

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

// A first MIDlet with simple text and a few commands.
public class FewCommandsMIDlet extends MIDlet
		         implements CommandListener {

  //The exit, info, and about commands
  private Command exitCommand;
  private Command infoCommand;
  private Command aboutCommand;

  //The display for this MIDlet
  private Display display;

  public FewCommandsMIDlet() {
    display = Display.getDisplay(this);
    exitCommand = new Command("离开",Command.SCREEN, 1);
    infoCommand = new Command("信息", Command.SCREEN, 2);

    aboutCommand = new Command("关于", Command.SCREEN, 2);
  }

  // Start the MIDlet by creating the TextBox and
  // associating the exit command and listener.
  public void startApp() {
    TextBox t = new TextBox("多个软键",
		    "Welcome to MIDP Programming", 256, 0);

    t.addCommand(infoCommand);
    t.addCommand(exitCommand);

    t.addCommand(aboutCommand);
    t.setCommandListener(this);
    display.setCurrent(t);
  }

  // Pause is a no-op because there are no background
  // activities or record stores to be closed.
  public void pauseApp() { }

  // Destroy must cleanup everything not handled
  // by the garbage collector.
  // In this case there is nothing to cleanup.
  public void destroyApp(boolean unconditional) { }

  // Respond to commands. Here we are only implementing
  // the exit command. In the exit command, cleanup and
  // notify that the MIDlet has been destroyed.
  public void commandAction(Command c, Displayable s) {
    if (c == exitCommand) {
      destroyApp(false);
      notifyDestroyed();
    }
  }
}