ui_low4.java

java手机/PDA程序开发与设计用户界面源代码UI_Low4.rar

// 程序名UI_Low4.java
// 测试按键事件和Command命令
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class UI_Low4 extends MIDlet implements CommandListener{
  private Display  display;
  private MyCanvas canvas;
  private Command cmdExit;
  private Command cmdRepaint;
  public UI_Low4(){
    display = Display.getDisplay( this );
    canvas  = new MyCanvas( this );
    cmdExit = new Command("Exit",Command.SCREEN,1);
    cmdRepaint = new Command("Repaint",Command.SCREEN,1);
    canvas.addCommand(cmdExit);
    canvas.addCommand(cmdRepaint);
    canvas.setCommandListener(this);
  }

  protected void startApp(){
    display.setCurrent( canvas );
  }
   
  protected void pauseApp(){
  }
  
  protected void destroyApp( boolean unconditional ){
  }

  public void commandAction( Command c, Displayable d ){
    if (c == cmdRepaint) {
      canvas.message = "command called.";
      canvas.repaint();
      System.out.println("command called.");
      return;
    }
    if (c == cmdExit){
      exit();
    }
  }

  public void exit(){
    destroyApp( true );
    notifyDestroyed();
  }
}