因为company项目中需要做九宫格抽奖活动，以前都没有做过类似的功能，虽然之前在浏览大神们的博客中，无意中也看到了好多关于抽奖的项目，但因为项目中没有需要，一直都没有点击进去看。这次不去看估计不行。直到公司计划要做抽奖功能，才迫不得已上网查找demo
网上找了大半天，好不容易找到了几个demo，下载下来，解压缩包发现竟然里面空空如也，只有几张九宫格的图片，害我白白浪费了几个CSDN积分。后面在eoe网站那发现了一个demo，于是好开心，下载下来后马上导入到工程中，运行看了效果，九宫格是出来了，但效果真不敢恭维，主要是运行不流畅。但我还是进去稍微看了一下demo，基本思路是这样的：定义好九宫格界面，然后开启子线程不断循环修改状态，再通过handler发送消息到主线程中修改界面（子线程不能直接修改界面）。
这个demo虽然功能上实现了，但不是我想要的效果，因为我这一关都不能通过，到了产品那边更加不用说了。那怎么办呢？
于是我想到了一个控件，叫做SurfaceView,做游戏开发的同志们，应该对这个控件不陌生吧？首先介绍一下这个控件：
1.SurfaceView继承于View，多用于游戏开发中
2.可以直接在子线程中运行（其他UI控件都必须在主线程中运行的）。
3.一般的UI控件自定义时都是重写onDraw方法，但在SurfaceView中是通过SurfaceHolder获取Canvas来绘制图形的
好了，来吧各位，先来看看效果图：
这样，下面我开始根据我的想法，把自定义九宫格的步骤说一下。
步骤：
1.计算各位方块的位置
2.绘制每个奖品的方块（主要让界面更加好看）
3.绘制奖品图
4.计算旋转方块的下一步位置
5.绘制旋转方块
6.监听点击开始按钮事件
主要核心技术：
SurfaceView，SurfaceHolder
OK，有了基本步骤，接下来就是根据步骤一步一步来进行了。
在开始绘制九宫格之前，我们先重写onMeasure方法，主要是为了让九宫格成为一个正方形，这样看起来体验更好，基本代码如下：
public class LotteryView extends SurfaceView{
/**
* holder
*/
private SurfaceHolder mHolder;
private List<Prize>prizes;
private boolean flags; //抽奖开关
private int lottery=6; //设置中奖号码
private int current=2; //抽奖开始的位置
private int count=0; //旋转次数累计
private int countDown; //倒计次数，快速旋转完成后，需要倒计多少次循环才停止
//旋转抽奖的方块默认颜色
private int transfer= 0xffff0000;
private int MAX=50; //最大旋转次数
/**
* 重新测量
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = Math.min(getMeasuredWidth(), getMeasuredHeight());
setMeasuredDimension(width, width);
}
}
SurfaceView一般不是通过重写onDraw方法来绘制控件的，那么怎么获取到Canvas呢？主要是通过SurfaceHolder监听Callback事件来获取的
基本代码如下：
/**
* holder
*/
private SurfaceHolder mHolder;
public LotteryView(Context context, AttributeSet attrs) {
super(context, attrs);
mHolder = this.getHolder();
//监听CallBack
mHolder.addCallback(this);
}
public LotteryView(Context context) {
this(context,null);
}现在有了对象SurfaceHolder对象，我们就可以获取到Canvas对象了，下面开始真正的绘制工作。
1.计算方块的具体显示位置
2.绘制每个奖品的方块
//绘制背景
private void drawBg(Canvas canvas) {
//清除已绘制的图形
canvas.drawColor(Color.WHITE, Mode.CLEAR);
//获取控件的宽度，因为要绘制九宫格，所以要平局分成三列
int width = getMeasuredWidth()/3;
int x1=0;
int y1=0;
int x2=0;
int y2=0;
int len = (int) Math.sqrt(prizes.size());
for(int x=0;x<len*len;x++){
Prize prize = prizes.get(x);
int index=x;
x1=getPaddingLeft()+width*(Math.abs(index)%len);
y1=getPaddingTop()+width*(index/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1,y1,x2,y2);
Paint paint=new Paint();
//绘制方块
canvas.drawRect(rect, paint);
}
}解析：prizes 是一个集合，里面封装了奖品的一些基本信息，x1,y1,x2,y2分别是绘制奖品容器正方形的左上顶点和右下顶点，
通过观察发现，每一个方块位置都有一定的关系，即 x1=getPaddingLeft()+width*(Math.abs(index)%len);
y1=getPaddingTop()+width*(index/len);
x2=x1+width;
y2=y1+width;
有了这些点的关系，就可以通过canvas.drawRect(rect, paint);绘制出方块了
3.绘制奖品图
//绘制奖品
private void drawPrize(Canvas canvas) {
int width = getMeasuredWidth()/3;
int x1=0;
int y1=0;
int x2=0;
int y2=0;
int len = (int) Math.sqrt(prizes.size());
for(int x=0;x<len*len;x++){
Prize prize = prizes.get(x);
int index=x;
x1=getPaddingLeft()+width*(Math.abs(index)%len);
y1=getPaddingTop()+width*(index/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1+width/6,y1+width/6,x2-width/6,y2-width/6);
prize.setRect(rect);
canvas.drawBitmap(prize.getIcon(), null, rect, null);
}
}通过了步骤1,2知道了方块的位置关系，就可以轻松的根据这些关系绘制出奖品来，Rect rect=new Rect(x1+width/6,y1+width/6,x2-width/6,y2-width/6);是让奖品比方块缩小一些，这样看起来会更自然一点。
4.计算旋转方块的下一步位置
//下一步
public int next(int position,int len){
int current=position;
if(current+1<len){
return ++current;
}
if((current+1)%len==0&¤t<len*len-1){
return current+=len;
}
if(current%len==0){
return current-=len;
}
if(current<len*len){
return --current;
}
return current;
}position是当前旋转方块的位置，len是3
5.绘制旋转方块
//绘制旋转的方块
private void drawTransfer(Canvas canvas) {
int width = getMeasuredWidth()/3;
int x1;
int y1;
int x2;
int y2;
int len = (int) Math.sqrt(prizes.size());
//得到下一步方块的位置
current=next(current, len);
x1=getPaddingLeft()+width*(Math.abs(current)%len);
y1=getPaddingTop()+width*((current)/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1,y1,x2,y2);
Paint paint=new Paint();
paint.setColor(transfer);
canvas.drawRect(rect, paint);
}6.监听点击开始按钮事件
private OnTransferWinningListener listener;
public void setOnTransferWinningListener(OnTransferWinningListener listener){
this.listener=listener;
}
public interface OnTransferWinningListener{
/**
* 中奖回调
* @param position
*/
void onWinning(int position);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
handleTouch(event);
return super.onTouchEvent(event);
}
/**
* 触摸
* @param event
*/
public void handleTouch(MotionEvent event) {
Point touchPoint=new Point((int)event.getX()-getLeft(),(int)event.getY());
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
Prize prize = prizes.get(Math.round(prizes.size())/2);
if(prize.isClick(touchPoint)){
if(!flags){
setStartFlags(true);
prize.click();
}
}
break ;
default:
break ;
}
}
//控制旋转
private void controllerTransfer() {
if(count>MAX){
countDown++;
SystemClock.sleep(count*5);
}else{
SystemClock.sleep(count*2);
}
count++;
if(countDown>2){
if(lottery==current){
countDown=0;
count=0;
setStartFlags(false);
if(listener!=null){
//切换到主线程中运行
post(new Runnable() {
@Override
public void run() {
listener.onWinning(current);
}
});
}
}
}
}至此，基本的自定义工作已经差不多了，使用demo如下：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.example.test.LotteryView
android:id="@+id/nl"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
public class HomeActivity extends Activity {
LotteryView nl;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_home);
nl=(LotteryView) findViewById(R.id.nl);
int[]prizesIcon={R.drawable.danfan,R.drawable.meizi,R.drawable.iphone,R.drawable.f015,R.drawable.arrow,R.drawable.f040,R.drawable.ipad,R.drawable.spree_icon,R.drawable.spree_success_icon};
final List<Prize>prizes=new ArrayList<Prize>();
for(int x=0;x<9;x++){
Prize lottery=new Prize();
lottery.setId(x+1);
lottery.setName("Lottery"+(x+1));
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), prizesIcon[x]);
lottery.setIcon(bitmap);
if((x+1)%2==0){
lottery.setBgColor(0xff4fccee);
}else if(x==4){
lottery.setBgColor(0xffffffff);
}else{
lottery.setBgColor(0xff00ff34);
}
prizes.add(lottery);
}
nl.setPrizes(prizes);
nl.setOnTransferWinningListener(new OnTransferWinningListener() {
@Override
public void onWinning(int position) {
Toast.makeText(getApplicationContext(), prizes.get(position).getName(), Toast.LENGTH_SHORT).show();
}
});
}
}运行效果非常流畅
LotteryView整体demo：
package com.example.test;
import java.util.List;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.PorterDuff;
import android.graphics.PorterDuff.Mode;
import android.graphics.Rect;
import android.os.SystemClock;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
public class LotteryView extends SurfaceView implements Callback{
/**
* holder
*/
private SurfaceHolder mHolder;
private List<Prize>prizes;
private boolean flags;
private int lottery=6; //设置中奖号码
private int current=2; //抽奖开始的位置
private int count=0; //旋转次数累计
private int countDown; //倒计次数，快速旋转完成后，需要倒计多少次循环才停止
private int transfer= 0xffff0000;
private int MAX=50; //最大旋转次数
private OnTransferWinningListener listener;
public void setOnTransferWinningListener(OnTransferWinningListener listener){
this.listener=listener;
}
public interface OnTransferWinningListener{
/**
* 中奖回调
* @param position
*/
void onWinning(int position);
}
/**
* 设置中奖号码
* @param lottery
*/
public void setLottery(int lottery) {
if(prizes!=null&&Math.round(prizes.size()/2)==0){
throw new RuntimeException("开始抽奖按钮不能设置为中奖位置！");
}
this.lottery = lottery;
}
/**
* 设置转盘颜色
* @param transfer
*/
public void setTransfer(int transfer) {
this.transfer = transfer;
}
/**
* 设置奖品集合
* @param prizes
*/
public void setPrizes(List<Prize>prizes){
this.prizes=prizes;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
handleTouch(event);
return super.onTouchEvent(event);
}
/**
* 触摸
* @param event
*/
public void handleTouch(MotionEvent event) {
Point touchPoint=new Point((int)event.getX()-getLeft(),(int)event.getY());
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
Prize prize = prizes.get(Math.round(prizes.size())/2);
if(prize.isClick(touchPoint)){
if(!flags){
setStartFlags(true);
prize.click();
}
}
break ;
default:
break ;
}
}
private class SurfaceRunnable implements Runnable{
@Override
public void run() {
while(flags){
Canvas canvas=null;
try {
canvas = mHolder.lockCanvas();
drawBg(canvas);
drawTransfer(canvas);
drawPrize(canvas);
controllerTransfer();
} catch (Exception e) {
e.printStackTrace();
}finally{
//涓轰簡璁╂瘡娆＄粯鍒跺浘褰㈡椂鑳藉椤哄埄杩涜锛屾渶濂藉皢瑙ｉ攣鏀惧埌寮傚父涓繘琛屽鐞嗭紝涔熷氨鏄锛屽鏋渃anvas涓嶄负绌猴紝閮藉皢鍏跺叧闂紝璁╀笅涓�娆″惊鐜兘澶熼『鍒╄繘琛岀粯鍒�
if(canvas!=null)
mHolder.unlockCanvasAndPost(canvas);
}
}
}
}
//绘制背景
private void drawBg(Canvas canvas) {
canvas.drawColor(Color.WHITE, Mode.CLEAR);
int width = getMeasuredWidth()/3;
int x1=0;
int y1=0;
int x2=0;
int y2=0;
int len = (int) Math.sqrt(prizes.size());
for(int x=0;x<len*len;x++){
Prize prize = prizes.get(x);
int index=x;
x1=getPaddingLeft()+width*(Math.abs(index)%len);
y1=getPaddingTop()+width*(index/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1,y1,x2,y2);
Paint paint=new Paint();
paint.setColor(prize.getBgColor());
canvas.drawRect(rect, paint);
}
}
//绘制旋转的方块
private void drawTransfer(Canvas canvas) {
int width = getMeasuredWidth()/3;
int x1;
int y1;
int x2;
int y2;
int len = (int) Math.sqrt(prizes.size());
current=next(current, len);
x1=getPaddingLeft()+width*(Math.abs(current)%len);
y1=getPaddingTop()+width*((current)/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1,y1,x2,y2);
Paint paint=new Paint();
paint.setColor(transfer);
canvas.drawRect(rect, paint);
}
//控制旋转
private void controllerTransfer() {
if(count>MAX){
countDown++;
SystemClock.sleep(count*5);
}else{
SystemClock.sleep(count*2);
}
count++;
if(countDown>2){
if(lottery==current){
countDown=0;
count=0;
setStartFlags(false);
if(listener!=null){
//切换到主线程中运行
post(new Runnable() {
@Override
public void run() {
listener.onWinning(current);
}
});
}
}
}
}
public void setStartFlags(boolean flags){
this.flags=flags;
}
//绘制奖品
private void drawPrize(Canvas canvas) {
int width = getMeasuredWidth()/3;
int x1=0;
int y1=0;
int x2=0;
int y2=0;
int len = (int) Math.sqrt(prizes.size());
for(int x=0;x<len*len;x++){
Prize prize = prizes.get(x);
int index=x;
x1=getPaddingLeft()+width*(Math.abs(index)%len);
y1=getPaddingTop()+width*(index/len);
x2=x1+width;
y2=y1+width;
Rect rect=new Rect(x1+width/6,y1+width/6,x2-width/6,y2-width/6);
prize.setRect(rect);
canvas.drawBitmap(prize.getIcon(), null, rect, null);
}
}
public void start() {
setLottery(getRandom());
ExecutorService service = Executors.newCachedThreadPool();
service.execute(new SurfaceRunnable());
}
//获取随机中奖数，实际开发中一般中奖号码是服务器告诉我们的
private int getRandom(){
Random r=new Random();
int nextInt =r.nextInt(prizes.size());
if(nextInt%(Math.round(prizes.size()/2))==0){
//随机号码等于中间开始位置，需要继续摇随机号
return getRandom();
}
return nextInt;
}
//下一步
public int next(int position,int len){
int current=position;
if(current+1<len){
return ++current;
}
if((current+1)%len==0&¤t<len*len-1){
return current+=len;
}
if(current%len==0){
return current-=len;
}
if(current<len*len){
return --current;
}
return current;
}
public LotteryView(Context context, AttributeSet attrs) {
super(context, attrs);
mHolder = this.getHolder();
mHolder.addCallback(this);
}
public LotteryView(Context context) {
this(context,null);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
Canvas canvas=null;
try {
canvas = mHolder.lockCanvas();
drawBg(canvas);
drawPrize(canvas);
Prize prize = prizes.get(Math.round(prizes.size()/2));
prize.setListener(new Prize.OnClickListener() {
@Override
public void onClick() {
start();
}
});
} catch (Exception e) {
e.printStackTrace();
}finally{
if(canvas!=null)
mHolder.unlockCanvasAndPost(canvas);
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
setStartFlags(false);
}
/**
* 重新测量
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = Math.min(getMeasuredWidth(), getMeasuredHeight());
setMeasuredDimension(width, width);
}
}