backtiledlayer.java

《Java程序设计实践教程》代码

/***************************************************
*  程序文件名称：　BackTiledLayer.java
*  功能：显示用户操作界面
***************************************************/
 import javax.microedition.midlet.*; 
 import javax.microedition.lcdui.*; 

public class BackTiledLayer extends MIDlet implements CommandListener
{ 
  private Display display; 
  private BackCanvas gameCanvas;  
  private Command cmdExit , cmdStart;
  
  public BackTiledLayer()
 {
  display = Display.getDisplay(this);
  cmdExit  = new Command("退出",Command.EXIT,1);
  cmdStart = new Command( "开始游戏", Command.OK,0);
  gameCanvas = new BackCanvas();
  gameCanvas.addCommand(cmdExit);
  gameCanvas.addCommand(cmdStart);
  gameCanvas.setCommandListener(this);
 } 
  
  public void startApp() { 
     display.setCurrent(gameCanvas); 
   } 

 public void pauseApp() { 
  } 

 public void destroyApp(boolean unconditional) { 
  } 

 public void commandAction(Command c,Displayable d)
	{
		if (c==cmdExit)
		{
			destroyApp(false);
			notifyDestroyed();
		}
		else if (c==cmdStart)
		{
		   gameCanvas.start(); 
		}
	} 
}