粒子效果的简单实现

1.封装一个粒子对象类：

/*************************
 *@author 徐宏明    E-Mail：android_xhm.126.com
 *                                        QQ:294985925
 *@version 创建时间            ：2013-5-28 上午10:56:48
 *
 *@see
 *************************/
package com.example.mytest;

public class Particle {
    int p_radius;// 粒子的半径
    double v_s, h_s;// 粒子的垂直和水平速度
    int p_color;// 粒子的颜色
    int startX, startY;// 粒子开始的位置
    int contentX, contentY;// 粒子的实时位置
    double contenttime;// 粒子开始的时间

    public Particle(int r, double vs, double hs, int color, int contentX,
            int contentY,double time) {
        // TODO Auto-generated constructor stub
        this.p_radius = r;
        this.v_s = vs;
        this.h_s = hs;
        this.p_color = color;
        this.startX = contentX;
        this.startY = contentY;
        this.contentX = contentX;
        this.contentY = contentY;
        this.contenttime = time;
    }
}

2.创建粒子对象类：

/*************************
 *@author 徐宏明    E-Mail：android_xhm.126.com
 *                                        QQ:294985925
 *@version 创建时间            ：2013-5-28 上午11:08:48
 *
 *@see
 *************************/
package com.example.mytest;

import java.util.ArrayList;

import android.graphics.Color;

public class GetParticles {
    ArrayList<Particle> particles;

    public GetParticles() {
        // TODO Auto-generated constructor stub
        particles = new ArrayList<Particle>();
    }

    /*
     * 增加粒子数量
     * 
     * @param count 一次增加的个数
     * 
     * @param time 增加粒子的起始时间
     */
    public void addParticle(int count, double time) {
        for (int i = 0; i < count; i++) {
            int r = 1;// 粒子的半径
            int color = getColor(i);// 粒子的颜色
            double h_s = 5;
            double v_s = 3;// 垂直速度
            int x = 160;
            int y = (int) (100 - 10 * (Math.random())); // 随机产生粒子Y坐标
            particles.add(new Particle(r, v_s, h_s, color, x, y, time));
        }
    }

    // 为粒子设置颜色
    private int getColor(int i) {
        int color = Color.RED;
        switch (i % 4) {
        case 0:
            color = Color.RED;
            break;
        case 1:
            color = Color.GREEN;
            break;
        case 2:
            color = Color.BLUE;
            break;
        case 3:
            color = Color.YELLOW;
            break;
        default:
            break;
        }
        return color;
    }
}

3.粒子坐标变化类：

/*************************
 *@author 徐宏明    E-Mail：android_xhm.126.com
 *                                        QQ:294985925
 *@version 创建时间            ：2013-5-28 上午11:30:28
 *
 *@see
 *************************/
package com.example.mytest;

/**
 * 计算当前粒子的位置，超出范围的粒子移除集合
 * 
 * @author 宏明
 * 
 */
public class ParticleChangeThread extends Thread {
    // 获得粒子的类
    private GetParticles particles;
    // 线程控制标识
    public boolean isRun;
    // 粒子坐标变化进步量
    private double span = 0.15;

    public ParticleChangeThread(MySurface surface) {
        // TODO Auto-generated constructor stub
        particles = surface.getParticles;
        this.isRun = true;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        super.run();
        double time = 0;
        while (isRun) {
            // 每次循环添加5个粒子
            particles.addParticle(5, time);
            for (int i = 0; i < particles.particles.size(); i++) {
                Particle p = particles.particles.get(i);
                double timespan = time - p.contenttime; // 获得粒子X坐标
                p.contentX = (int) (p.startX + timespan * p.h_s);
                p.contentY = (int) (p.startY + timespan * p.v_s);
                // 当粒子超过屏幕范围时，移除粒子
                if (p.contentY > 800 || p.contentY < 0 || p.contentX > 400
                        || p.contentX < 0) {
                    particles.particles.remove(p);
                }
            }
            time += span;
            try {
                sleep(60);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

4.画粒子线程：

/*************************
 *@author 徐宏明    E-Mail：android_xhm.126.com
 *                                        QQ:294985925
 *@version 创建时间            ：2013-5-28 下午4:23:18
 *
 *@see
 *************************/
package com.example.mytest;

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.view.SurfaceHolder;

public class DrawThread extends Thread {
    // 线程控制标识
    public boolean isRun;
    // surface控制对象
    private SurfaceHolder mHolder;
    // mysurface对象
    private MySurface mSurface;

    public DrawThread(SurfaceHolder holder, MySurface surface) {
        // TODO Auto-generated constructor stub
        mHolder = holder;
        mSurface = surface;
        this.isRun = true;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        super.run();
        Canvas c = null;

        while (isRun) {
            c = mHolder.lockCanvas();
            synchronized (mHolder) {
                draw(c);
            }
            if (c != null) {
                mHolder.unlockCanvasAndPost(c);
            }
            try {
                sleep(0);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    // 画粒子
    private void draw(Canvas c) {
        c.drawColor(Color.WHITE);
        Paint t = new Paint();
        for (int i = 0; i < mSurface.particles.size(); i++) {
            Particle p = mSurface.particles.get(i);
            t.setColor(p.p_color);
            RectF oval = new RectF(p.contentX, p.contentY, p.contentX + 2
                    * p.p_radius, p.contentY + 2 * p.p_radius);
            c.drawOval(oval, t);
        }
    }
}

5MySurface类：

/*************************
 *@author 徐宏明    E-Mail：android_xhm.126.com
 *                                        QQ:294985925
 *@version 创建时间            ：2013-5-28 下午4:25:45
 *
 *@see
 *************************/
package com.example.mytest;

import java.util.ArrayList;

import android.content.Context;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class MySurface extends SurfaceView implements SurfaceHolder.Callback {
    public ArrayList<Particle> particles;
    public GetParticles getParticles;
    private DrawThread draw;
    private ParticleChangeThread change;

    public MySurface(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        this.getHolder().addCallback(this);
        getParticles = new GetParticles();
        particles = getParticles.particles;
        draw = new DrawThread(getHolder(), this);
        change = new ParticleChangeThread(this);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        System.out.println(draw.isAlive());
        if (!draw.isAlive()) {
            draw.start();
        }
        if (!change.isAlive()) {
            change.start();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // TODO Auto-generated method stub

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        draw.isRun = false;
        draw = null;
        change.isRun = false;
        change = null;
    }

}