maincanvas.java

J2ME编程的50个例子,适合掌上系统的编程

package demo;
import MineMidlet;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.game.GameCanvas;

public class MainCanvas extends GameCanvas implements Runnable{
	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_END				= 2;	//游戏结束
	public static final int GAME_STATE_NUM 		= 3;	//状态总数
	private int m_nState	= GAME_UI;				//存储当前的游戏状态
	
	private boolean m_bRunning;					//控制游戏的运行
	private MyUI m_UI;								//用户界面			
	private Grids m_Grids;							//格子对象
	public MainCanvas( ){
		super(false);								//参数为false，表示响应keyPressed方法
		try{
			m_Grids = new Grids(10, 10, getWidth(), getHeight());
			m_Grids.ResetMines( 20 );
			
			MyButton button = new MyButton();
			m_UI = new MyUI(button);
        }
        catch(Exception exception){}
        setState(GAME_UI);
		Start();
	}
	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
			break;
		case GAME_GAMING:									//正在游戏
			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 > 100 ){			//间隔100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:										//进入用户界面
			{
				switch( m_UI.Input( keyStates ) ){
				case MyButton.BUTTON_START:					//按下开始键
					setState(GAME_GAMING);
					break;
				case MyButton.BUTTON_EXIT:					//按下退出键
					MineMidlet.m_Midlet.notifyDestroyed();
					break;
				}
			}
			break;			
		case GAME_GAMING:									//游戏中
			if( ( keyStates & GameCanvas.UP_PRESSED ) != 0 )
				m_Grids.m_nCurRow --;		//选择上一行的方块
			if( ( keyStates & GameCanvas.DOWN_PRESSED ) != 0 )
				m_Grids.m_nCurRow ++;		//选择下一行的方块
			if( ( keyStates & GameCanvas.LEFT_PRESSED ) != 0 )
				m_Grids.m_nCurCol --;		//选择左列的方块
			if( ( keyStates & GameCanvas.RIGHT_PRESSED ) != 0 )
				m_Grids.m_nCurCol ++;		//选择右列的方块
		
			//对所选方块的位置，进行安全检测
			if( m_Grids.m_nCurCol < 0 )
				m_Grids.m_nCurCol = 0;
			if( m_Grids.m_nCurCol >= m_Grids.m_GridTL.getColumns() )
				m_Grids.m_nCurCol = m_Grids.m_GridTL.getColumns() - 1;
			if( m_Grids.m_nCurRow < 0 )
				m_Grids.m_nCurRow = 0;
			if( m_Grids.m_nCurRow >= m_Grids.m_GridTL.getRows() )
				m_Grids.m_nCurRow = m_Grids.m_GridTL.getRows() - 1;
			
			if( ( keyStates & GameCanvas.FIRE_PRESSED ) != 0 )
			{//按下中心键，进行“挖雷”操作
				if( m_Grids.DigMine( m_Grids.m_nCurCol, m_Grids.m_nCurRow ) )
				{//如果挖到地雷，则显示所有的地雷
					m_Grids.ShowAllMines();
					setState(GAME_END);
				}
			}
			break;
		}
	}
	public void Logic(){
	}
	public void Paint(){
		Graphics g = getGraphics();
		//用黑色清屏
		g.setColor(0);
		g.fillRect( 0, 0, getWidth(), getHeight() );
		
		g.setColor(0x0000FF);
		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
			m_Grids.Paint(g);
			break;
		case GAME_END:								//显示结束画面
			m_Grids.Paint(g);
			g.drawString("游戏失败", 20, 20, 0 );
			break;
		}
		flushGraphics();
	}
}