mycanvas.java

这是一个非常好的手几上的J2ME应用程序可以帮助初学者

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;
import java.io.IOException;
public class MyCanvas extends GameCanvas implements Runnable,CommandListener  
{
  private LayerManagerDemo midlet;//程序控制类
  private volatile Thread animationThread=null;//线程
  private TiledLayer mBackground;//地图
  private LayerManager mLayerManager;
  private int canvasHeight, canvasWidth;//屏幕高度/宽度
  private static int tileHeight,tileWidth;//地图的高度/
  private static int columns,rows;
  private static int mapWidth,mapHeight;

  private boolean isRun;  
  private int curX,curY;//当前viewer坐标
  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();//创建背景
    }catch(IOException e){
    System.out.println("create error");
    }
    mLayerManager = new LayerManager();//创建层管理实例
    mLayerManager.append(mBackground);//添加地图
    exit=new Command("Exit", Command.STOP,1);
    this.addCommand(exit);
    this.setCommandListener(this);//两个按键
   }
 
  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");//创建背景图片
    TiledLayer tiledLayer = new TiledLayer(5, 5, image, 78, 36);//注意：背景的参数的设置！
    int LEA = 1;//草地lea
    int FLD = 2;//田地filed
    int HSE = 3;//房子house
    int TRE = 4;//树木tree
    int WOD = 5;//树丛wood
    int LAK = 6;//湖泊lake
    tileWidth = 78;
    tileHeight = 36; 
    columns = 5;
    rows = 5;
    mapWidth =tileWidth*columns;
    mapHeight = tileHeight*rows;
    int[] map = {//地图数组
       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,
    };//显示地图
    
    for (int i = 0; i < map.length; i++) {
      int column = i % columns;
      int row = (i - column) / columns;
      tiledLayer.setCell(column, row, map[i]);//通过一个循环来设置tiledLayer
    }
    return tiledLayer;//返回
  }
  private void input(){
  int keyState = getKeyStates(); //获得键盘状态
  if ((keyState & LEFT_PRESSED) != 0) { //如果左键被按下
      curX = curX - xOffset;
     // if(curX >= 0)curX=0;     
   
  }
  if ((keyState & RIGHT_PRESSED) != 0) { //如果右键被按下
      curX = curX + xOffset;
     // if(curX  <= -mapWidth + canvasWidth)curX = -mapWidth + canvasWidth;
  }
  if ((keyState & UP_PRESSED) != 0) { //如果上键被按下
  
   curY = curY - yOffset;
   //if(curY >= 0)curY=0;
   
  }
  if ((keyState & DOWN_PRESSED) != 0) { //如果下键被按下
    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();
    }

  }

 
 
}