maincanvas.java

J2ME编程的50个例子,适合掌上系统的编程

package demo;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.game.GameCanvas;


public class MainCanvas extends GameCanvas implements Runnable{
	private boolean	m_bRunning;				//控制项目运行
	public int	m_nWidth = 50;					//显示宽度
	public Font m_Font;							//存储字体
	public MainCanvas(){
		super(true);
		//创建字体，如果创建失败，则采用系统默认字体
		try{
			m_Font 	= Font.getFont(Font.FACE_SYSTEM, 
							Font.STYLE_PLAIN, Font.SIZE_LARGE );
		}catch(Exception e){
			m_Font  = Font.getDefaultFont();
		}
		Start();								//启动线程
	}
	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() {						//新线程自动调用此方法
		//获得系统当前时间,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(){						//终止游戏
		m_bRunning = false;
	}
	public void Input(){
		int keyStates = getKeyStates();			//获取当前按键状态
		//如果按下方向键的上键，则调整显示宽度		
		if( ( keyStates & GameCanvas.UP_PRESSED ) != 0 )	
			m_nWidth = m_nWidth +10; 		
		//如果按下方向键的下键，则调整显示宽度		
		if( ( keyStates & GameCanvas.DOWN_PRESSED ) != 0 )			
			m_nWidth = m_nWidth -10;
	}
	public void Logic(){
	}
	public void Paint(){
		Graphics g = getGraphics();
		//用黑色清屏
		g.setColor(0x00000000);
		g.fillRect( 0, 0, getWidth(), getHeight() );
		g.setFont(m_Font);
		g.setColor(0x00FFFFFF);
		TextAjust.AjustDrawString(g, 
				"我要自动换行我要自动换行我要自动换行我要自动换行",
				m_nWidth, 20, 20, 15 );
		
		flushGraphics();
	}
}