首先上效果，美女配雪景还是头一回哈哈！程序猿们别流口水哈！

首先新建一个SnowView类具体实现如下

package com.weixin.view;


import com.weixin.contants.SnowFlake;


import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

/**
 * 雪花视图, DELAY时间重绘, 绘制NUM_SNOWFLAKES个雪花
 */
public class SnowView extends View {


    private static final int NUM_SNOWFLAKES = 150; // 雪花数量
    private static final int DELAY = 5; // 延迟
    private SnowFlake[] mSnowFlakes; // 雪花

    public SnowView(Context context) {
        super(context);
    }

    public SnowView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SnowView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override 
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        if (w != oldw || h != oldh) {
            initSnow(w, h);
        }
    }

    private void initSnow(int width, int height) {
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); // 抗锯齿
        paint.setColor(Color.WHITE); // 雪花颜色白色
        paint.setStyle(Paint.Style.FILL); // 填充;
        mSnowFlakes = new SnowFlake[NUM_SNOWFLAKES];
        //mSnowFlakes所有的雪花都生成放到这里面，循环雪花
        for (int i = 0; i < NUM_SNOWFLAKES; ++i) {
            mSnowFlakes[i] = SnowFlake.create(width, height, paint);
        }
    }


    @Override 
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //for返回SnowFlake
        for (SnowFlake s : mSnowFlakes) {
        //然后进行绘制
            s.draw(canvas);
        }
        // 隔一段时间重绘一次, 动画效果
        getHandler().postDelayed(runnable, DELAY);
    }


    // 重绘线程
    private Runnable runnable = new Runnable() {
        @Override
        public void run() {
        //自动刷新
            invalidate();
        }
    };
}

布局文件这里是自定义的view改成你自己的报名com+packagename+view

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/gril" >
        <com.weixin.view.SnowView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:paddingLeft="10dp" />
    </FrameLayout>
</LinearLayout>

然后创建SnowFlake类

package com.weixin.contants;


import com.weixin.util.RandomGenerator;


import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;


public class SnowFlake {
/**
* 常量
*/
// 雪花的角度
    private static final float ANGE_RANGE = 0.1f; // 角度范围
    private static final float HALF_ANGLE_RANGE = ANGE_RANGE / 2f; // 一般的角度
    private static final float HALF_PI = (float) Math.PI / 2f; // 半PI
    private static final float ANGLE_SEED = 25f; // 角度随机种子
    private static final float ANGLE_DIVISOR = 10000f;
    // 雪花的移动速度
    private static final float INCREMENT_LOWER = 2f;
    private static final float INCREMENT_UPPER = 4f;


    // 雪花的大小
    private static final float FLAKE_SIZE_LOWER = 7f;
    private static final float FLAKE_SIZE_UPPER = 20f;


    private final RandomGenerator mRandom; // 随机控制器
    private final Point mPosition; // 雪花位置
    private float mAngle; // 角度
    private final float mIncrement; // 雪花的速度
    private final float mFlakeSize; // 雪花的大小
    private final Paint mPaint; // 画笔


    private SnowFlake(RandomGenerator random, Point position, float angle, float increment, float flakeSize, Paint paint) {
        mRandom = random;
        mPosition = position;
        mIncrement = increment;
        mFlakeSize = flakeSize;
        mPaint = paint;
        mAngle = angle;
    }


    public static SnowFlake create(int width, int height, Paint paint) {
        RandomGenerator random = new RandomGenerator();
        int x = random.getRandom(width);
        int y = random.getRandom(height);
        Point position = new Point(x, y);
        float angle = random.getRandom(ANGLE_SEED) / ANGLE_SEED * ANGE_RANGE + HALF_PI - HALF_ANGLE_RANGE;
        float increment = random.getRandom(INCREMENT_LOWER, INCREMENT_UPPER);
        float flakeSize = random.getRandom(FLAKE_SIZE_LOWER, FLAKE_SIZE_UPPER);
        return new SnowFlake(random, position, angle, increment, flakeSize, paint);
    }


    // 绘制雪花
    public void draw(Canvas canvas) {
        int width = canvas.getWidth();
        int height = canvas.getHeight();
        move(width, height);
        canvas.drawCircle(mPosition.x, mPosition.y, mFlakeSize, mPaint);
    }


    // 移动雪花
    private void move(int width, int height) {
    //x水平方向，那么需要晃动，主要设置这个值就可以，现在取消晃动了
    //如果 mPosition.x不加上后面那个值，就不会晃动了
    double x = mPosition.x + (mIncrement * Math.cos(mAngle));
        //y是竖直方向，就是下落
        double y = mPosition.y + (mIncrement * Math.sin(mAngle));
 
        mAngle += mRandom.getRandom(-ANGLE_SEED, ANGLE_SEED) / ANGLE_DIVISOR;
        //这个是设置雪花位置，如果在很短时间内刷新一次，就是连起来的动画效果
        mPosition.set((int) x, (int) y);


        // 移除屏幕, 重新开始
        if (!isInside(width, height)) {
            // 重置雪花
            reset(width);
        }
    }
    
    // 判断是否在其中
    private boolean isInside(int width, int height) {
        int x = mPosition.x;
        int y = mPosition.y;
        return x > mFlakeSize -5 && x + mFlakeSize <= width && y >= -mFlakeSize - 1 && y - mFlakeSize < height;
    }


    // 重置雪花
    private void reset(int width) {
        mPosition.x = mRandom.getRandom(width);
        mPosition.y = (int) (-mFlakeSize - 1); // 最上面
        mAngle = mRandom.getRandom(ANGLE_SEED) / ANGLE_SEED * ANGE_RANGE + HALF_PI - HALF_ANGLE_RANGE;
    }
}

创建随机生成雪花类

package com.weixin.util;


import java.util.Random;


/**
 * 随机生成器工具类RandomGenerator
 */
public class RandomGenerator {
    private static final Random RANDOM = new Random();


    // 区间随机
    public float getRandom(float lower, float upper) {
        float min = Math.min(lower, upper);
        float max = Math.max(lower, upper);
        return getRandom(max - min) + min;
    }


    // 上界随机
    public float getRandom(float upper) {
        return RANDOM.nextFloat() * upper;
    }


    // 上界随机
    public int getRandom(int upper) {
        return RANDOM.nextInt(upper);
    }
    
}