enemysprite.java

J2ME编程的50个例子,适合掌上系统的编程

package demo;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.Sprite;


public class EnemySprite extends Sprite{
	public static final int ENEMY_NORMAL	= 0;	//正常状态
	public static final int ENEMY_BEHIT	= 1;	//被打状态
	private int m_nState = ENEMY_NORMAL;
	private int m_nLife;
	public EnemySprite(Image image, int frameWidth, int frameHeight) {
		super(image, frameWidth, frameHeight);
		defineReferencePixel(frameWidth / 2, frameHeight / 2);
		setVisible(false);
		defineCollisionRectangle(3, 7, 30, 17);
	}
	//产生敌人
	//参数nX、nY分别是敌人位置的横纵坐标
	public void Start( int nX, int nY ){
		setRefPixelPosition( nX, nY );
		m_nState = ENEMY_NORMAL;
		m_nLife = 4;
		setVisible( true );
	}
	//被攻击，参数ObjectX是攻击着的X坐标，参数scrWidth是屏幕的宽度
	public void BeHit( int ObjectX, int scrWidth ){
		int x = getRefPixelX();
		if( x < ObjectX ){
			if( x > 0 )
				x = x - 3;
		}
		else if( x < scrWidth )
			x = x + 3;
		setRefPixelPosition(x, getRefPixelY());
		m_nLife --;
		if( m_nLife <= 0 )
			setVisible(false);
		m_nState = ENEMY_BEHIT;
		
	}
	//逻辑操作
	public void Logic(){
		if( !isVisible() )
			return;
		switch( m_nState ){
		case ENEMY_NORMAL:
			setFrame(0);
			break;
		case ENEMY_BEHIT:
			setFrame(1);
			m_nState = ENEMY_NORMAL;
			break;
		}
	}
}