maincanvas.java

J2ME编程的50个例子,适合掌上系统的编程

package demo;
import BeanMidlet;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;

public class MainCanvas extends GameCanvas 
				implements Runnable, CommandListener{
	public static final int GAME_UI				= 0;	//进入用户界面
	public static final int GAME_GAMING			= 1;	//进行游戏
	public static final int GAME_BUTTON			= 2;	//游戏时显示界面按钮
	public static final int GAME_END				= 3;	//游戏结束
	public static final int GAME_STATE_NUM 		= 4;	//状态总数
	private int m_nState	= GAME_UI;						//存储当前的游戏状态
	
	private boolean		m_bRunning;			    		//控制线程运行
	private MyUI			m_UI;							//界面对象
	private ManSprite		m_Man;							//精灵对象
	private Grids			m_Grid;							//格子对象
	private EnemySprite	m_aEnemy[];						//敌人对象
	private Command 		MenuCommand;					//高级按钮对象
	public MainCanvas( ){
		super(true);	
		try{
			//创建用户界面，并设置界面中的按钮
			MyButton button = new MyButton(41, 21, 0, 1, -1, -1, -1, 2);
			m_UI = new MyUI(button);
        }
        catch(Exception exception){}
        //添加菜单
        MenuCommand 	= new Command("Menu", Command.OK, 0);
        //先不添加菜单按钮
        setCommandListener(this);
        setState(GAME_UI);
		Start();
	}
	//重新设置游戏
	private void Reset(){
		if( m_Grid == null ){
			//创建背景方格
			m_Grid = new Grids( getWidth(), getHeight() );
		}
		m_Grid.Reset();
		if( m_Man == null ){
			//创建吃豆的精灵
			try{
				Image imgMan = Image.createImage("/demo/sprite.png");
				m_Man = new ManSprite(imgMan, 13, 13);
			}
			catch(Exception exception){}
		}
		//设置吃豆精灵
		m_Man.Reset();
		m_Man.setBirth(4, 4, m_Grid);
		
		if( m_aEnemy == null ){
			try{
				//创建敌人
				Image imgEny = Image.createImage("/demo/enemy.png");
				m_aEnemy = new EnemySprite[2];
				for( int n = 0; n < m_aEnemy.length; n ++ ){
					m_aEnemy[n] = new EnemySprite(imgEny, 13, 13);
				}
			}
			catch(Exception exception){}
		}
		//设置敌人
		m_aEnemy[0].Start(1, 1, m_Grid);
		m_aEnemy[1].Start( 7, 6, m_Grid);
	}
	private void setState( int state ){					//设置游戏状态
		if( state < 0 || state >= GAME_STATE_NUM )
			return;
		m_nState = state;
		switch( m_nState ){
		case GAME_UI:										//进入用户界面
			m_UI.setState(MyUI.UI_TITLE);					//显示标题界面
			//设置本游戏的按钮类型，本游戏有:开始、退出两种按钮
			m_UI.getButton().setShow(true, false, false, false, false, true );
			break;
		case GAME_BUTTON:									//在游戏中途显示按钮
			m_UI.setState(MyUI.UI_BUTTON);
			//游戏中途，显示复位与退出按钮
			m_UI.getButton().setShow(false, true, false, false, false, true );
			break;
		case GAME_GAMING:									//正在游戏
			addCommand(MenuCommand);
			m_UI.setState(MyUI.UI_HIDE);
			break;
		case GAME_END:										//游戏结束
			m_UI.setState(MyUI.UI_HIDE);
			break;;
		}
	}
	public void Start(){
		m_bRunning = true;
		Thread thread = new Thread(this);	//分配新线程
		thread.start();						//线程启动
	}
	public void run() {
		//得到系统当前时间,并将时间换算成毫秒
		long T1 = System.currentTimeMillis();
		long T2 = T1;
		while(m_bRunning){
			T2 = System.currentTimeMillis();
			if( T2 - T1 > 50 ){				//间隔50毫秒
				T1 = T2;
				Input();
				Logic();
				Paint();
			}
		}
	}
	public void Stop(){
		m_bRunning = false;
	}
	public void Input(){
		int keyStates = getKeyStates();
		switch( m_nState ){
		case GAME_UI:
			{
				switch( m_UI.Input( keyStates ) ){
				case MyButton.BUTTON_START:					//按下开始键
					Reset();
					setState(GAME_GAMING);
					break;
				case MyButton.BUTTON_EXIT:					//按下退出键
					BeanMidlet.midlet.notifyDestroyed();
					break;
				}
			}
			break;			
		case GAME_GAMING:									//游戏中
			m_Man.input(keyStates, m_Grid);
			break;
		case GAME_BUTTON:									//游戏中途显示按钮
			{
				switch( m_UI.Input( keyStates ) ){
				case MyButton.BUTTON_RESET:					//按下复位键
					Reset();
					setState(GAME_GAMING);
					break;
				case MyButton.BUTTON_EXIT:					//按下退出键
					BeanMidlet.midlet.notifyDestroyed();
					break;
				}
			}
			break;
		case GAME_END:
			break;
		}
	}
	public void Logic(){
		switch( m_nState ){		
		case GAME_GAMING:									//游戏中
			m_Man.Logic(m_Grid);
			for( int n = 0; n < m_aEnemy.length; n ++ ){
				m_aEnemy[n].Logic(m_Grid, m_Man);
				if( m_Man.collidesWith( m_aEnemy[n], true ) )
				{//如果吃豆精灵和敌人碰撞
					switch( m_Man.getState() ){
					case ManSprite.MAN_STRONG:			//如果吃豆精灵很强壮
						//让敌人牺牲
						m_aEnemy[n].setState(EnemySprite.ENEMY_DEAD);
						break;
					case ManSprite.MAN_NORMAL:			//如果吃豆精灵正常
						if( m_aEnemy[n].getState() == EnemySprite.ENEMY_NORMAL )
						{//如果敌人正常，则让吃豆精灵牺牲
							m_Man.setState(ManSprite.MAN_DEAD);
							if( m_Man.getLife() <= 0 )
								setState(GAME_END);
						}
						break;
					}
				}
			}
			break;
		default:
			break;
		}
	}
	public void Paint(){
		Graphics g = getGraphics();
		//用黑色清屏
		g.setColor(0xFFFFFFFF);
		g.fillRect( 0, 0, getWidth(), getHeight() );
		
		g.setColor(0xFF000000);
		switch( m_nState ){
		case GAME_UI:								//显示界面
			m_UI.Paint(g, getWidth(), getHeight());
			break;			
		case GAME_GAMING:							//显示游戏画面
		case GAME_BUTTON:
		case GAME_END:
			m_Grid.Paint(g);
			m_aEnemy[0].paint(g);
			m_aEnemy[1].paint(g);
			m_Man.paint(g);
			m_UI.Paint(g, getWidth(), getHeight());
			if( m_nState == GAME_END )
				g.drawString("游戏结束", 20, 20, 0 );
			break;
		}
		flushGraphics();
	}
	public void commandAction(Command c, Displayable s){
		if( c == MenuCommand ){
			switch( m_nState ){	
			case GAME_END:							//游戏结束，显示按钮
			case GAME_GAMING:						//正在游戏，显示按钮	
				setState(GAME_BUTTON);
				break;
			case GAME_BUTTON:						//正显示按钮，退回游戏
				setState(GAME_GAMING);
				break;
			default:
				break;
			}
		}
	}
}