import javax.microedition.lcdui.*;import javax.microedition.lcdui.game.*;import java.io.IOException;public class MyCanvas extends GameCanvas implements Runnable,CommandListener  {  private LayerManagerDemo midlet;//程序控制類  private volatile Thread animationThread=null;//線程  private TiledLayer mBackground;//地圖  private LayerManager mLayerManager;  private int canvasHeight, canvasWidth;//屏幕高度/寬度  private static int tileHeight,tileWidth;//地圖的高度/  private static int columns,rows;  private static int mapWidth,mapHeight;  private boolean isRun;    private int curX,curY;//當前viewer坐標  private int xOffset = 5,yOffset = 5;    private final int SLEEP=10;  private Command exit;  public MyCanvas(LayerManagerDemo midlet)  {    super(true);    this.midlet = midlet;    canvasHeight=getHeight();    canvasWidth=getWidth();    try{    mBackground = createBackground();//創建背景    }catch(IOException e){    System.out.println("create error");    }    mLayerManager = new LayerManager();//創建層管理實例    mLayerManager.append(mBackground);//添加地圖    exit=new Command("Exit", Command.STOP,1);    this.addCommand(exit);    this.setCommandListener(this);//兩個按鍵   }   synchronized void start()  {    isRun=true;    animationThread=new Thread(this);    animationThread.start();  }  public void run()  {    Graphics g = this.getGraphics();    try    {      while (isRun)      {      	input();      	tick();      	render(g);        Thread.sleep(SLEEP);      }    }    catch(InterruptedException ie)    {      System.out.println(ie.toString());    }  }   private TiledLayer createBackground()throws IOException {    Image image = Image.createImage("/background.png");//創建背景圖片    TiledLayer tiledLayer = new TiledLayer(5, 5, image, 78, 36);//注意：背景的參數的設置！    int LEA = 1;//草地lea    int FLD = 2;//田地filed    int HSE = 3;//房子house    int TRE = 4;//樹木tree    int WOD = 5;//樹叢wood    int LAK = 6;//湖泊lake    tileWidth = 78;    tileHeight = 36;     columns = 5;    rows = 5;    mapWidth =tileWidth*columns;    mapHeight = tileHeight*rows;    int[] map = {//地圖數組       LEA,FLD,TRE,FLD,FLD,       LEA,LEA,LAK,WOD,LEA,       HSE,LEA,HSE,WOD,FLD,       WOD,LAK,HSE,LEA,WOD,       HSE,LEA,LEA,TRE,LAK,    };//顯示地圖        for (int i = 0; i < map.length; i++) {      int column = i % columns;      int row = (i - column) / columns;      tiledLayer.setCell(column, row, map[i]);//通過一個循環來設置tiledLayer    }    return tiledLayer;//返回  }  private void input(){  int keyState = getKeyStates(); //獲得鍵盤狀態  if ((keyState & LEFT_PRESSED) != 0) { //如果左鍵被按下      curX = curX - xOffset;     // if(curX >= 0)curX=0;          }  if ((keyState & RIGHT_PRESSED) != 0) { //如果右鍵被按下      curX = curX + xOffset;     // if(curX  <= -mapWidth + canvasWidth)curX = -mapWidth + canvasWidth;  }  if ((keyState & UP_PRESSED) != 0) { //如果上鍵被按下     curY = curY - yOffset;   //if(curY >= 0)curY=0;     }  if ((keyState & DOWN_PRESSED) != 0) { //如果下鍵被按下    curY = curY + yOffset;   //if(curY <= -mapHeight + canvasHeight)curY = -mapHeight + canvasHeight;  }  }  private void tick(){  //mBackground.setPosition(curX,curY); //  mLayerManager.setViewWindow(curX,curY,canvasWidth/2,canvasHeight/2);    }  private void render(Graphics g){  	mBackground.setPosition(50,50);  	mBackground.paint(g);  	//mLayerManager.paint(g,50, 50);  	            flushGraphics();    }  synchronized void stop()  {    isRun=false;  }  public void commandAction(Command c, Displayable d)  {    //if any Exit key is pressed then exit    if(c==exit)    {      midlet.exitMidlet();    }  }  }