最近的功能需求中需要实现用户使用签到获取的积分，可以在九宫格中进行抽奖消耗积分，这里使用的是自定义进行实现抽奖的功能，可以通过设置计算策略，来控制用户 中哪些奖以及中大奖 的概率，话不多说，直接上代码。
1.先看效果图
在这里插入图片描述
2.自定义View实现九宫格抽奖功能
代码语言：txt复制public class LuckyView extends View {
private Paint mPaint;
private float mStrokeWidth = 5;
private int mRepeatCount = 5; // 转的圈数
private int mRectSize; // 矩形的宽和高（矩形为正方形）
private boolean mShouldStartFlag;
private boolean mShouldStartNextTurn = true; // 标记是否应该开启下一轮抽奖
private int mStartLuckPosition = 0; // 开始抽奖的位置
private int mCurrentPosition = -1; // 当前转圈所在的位置
private OnLuckAnimationEndListener mLuckAnimationEndListener;
/**
* 可以通过对 mLuckNum 设置计算策略，来控制用户 中哪些奖 以及 中大奖 的概率
*/
private int mLuckNum = 3; // 默认最终中奖位置
private List<RectF> mRectFs; // 存储矩形的集合
private int[] mItemColor = {Color.parseColor("#ffefd6"), Color.parseColor("#ffefd6")}; // 矩形的颜色
private String[] mPrizeDescription = {"满20减1元券", "满10减1元券", "满30减2元券", "满5减1元券", "免单", "满300减40元券", "满100减10元券", "满500减50元券", "开始"};
private int[] mLuckyPrizes = {R.drawable.aaa, R.drawable.bbb, R.drawable.ccc, R.drawable
.ddd, R.drawable.aaa, R.drawable.bbb, R.drawable.ccc, R.drawable.ddd, R
.drawable.center_lucky};
private List<String> lettersBeans;
private float left;
private float top;
private Bitmap[] bitmaps;
private String[] luckyName;
private String[] id;
private int selectPos;
public LuckyView(Context context) {
this(context, null);
}
public LuckyView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public LuckyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); // 抗锯齿
mPaint.setStyle(Paint.Style.FILL);
// mPaint.setStyle(Paint.Style.STROKE); // 设置样式为描边
mPaint.setStrokeWidth(mStrokeWidth); // 设置描边的宽度
mRectFs = new ArrayList<>();
}
public void setLuckAnimationEndListener(OnLuckAnimationEndListener luckAnimationEndListener) {
mLuckAnimationEndListener = luckAnimationEndListener;
}
public int getLuckNum() {
return mLuckNum;
}
public void setLuckNum(int luckNum) {
mLuckNum = luckNum;
}
public int[] getLuckyPrizes() {
return mLuckyPrizes;
}
public void setLuckyPrizes(int[] luckyPrizes) {
mLuckyPrizes = luckyPrizes;
}
//设置图片，文字数据
public void setData(List<String> lettersBeans) {
this.lettersBeans = lettersBeans;
invalidate();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// 矩形的宽高
mRectSize = (Math.min(w, h)) / 3;
// 当控件大小改变的时候清空数据
mRectFs.clear();
initNineRect();
}
/**
* 初始化 9 个矩形（正方形）的位置信息
*/
private void initNineRect() {
final float width = getWidth();
// 加载前三个矩形
for (int i = 0; i < 3; i ) {
float left = i * mRectSize 5;
float right = (i 1) * mRectSize;
float top = 5;
float bottom = mRectSize;
RectF rectF = new RectF(left, top, right, bottom);
mRectFs.add(rectF);
}
// 加载第 4 个矩形
mRectFs.add(new RectF(width - mRectSize 5, mRectSize 5, width, 2 * mRectSize));
// 加载第 5~7 个矩形
for (int j = 3; j > 0; j--) {
float left = width - (4 - j) * mRectSize 5;
float right = width - (3 - j) * mRectSize;
float top = 2 * mRectSize 5;
float bottom = 3 * mRectSize;
RectF rectF = new RectF(left, top, right, bottom);
mRectFs.add(rectF);
}
// 加载第 8 个矩形
mRectFs.add(new RectF(5, mRectSize 5, mRectSize, 2 * mRectSize));
// 加载中心第 9 个矩形
mRectFs.add(new RectF(mRectSize 5, mRectSize 5, 2 * mRectSize, 2 * mRectSize));
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//执行真正的绘制矩形操作
drawNineRect(canvas);
// 填充奖品图片
drawNineBitmaps(canvas);
// 填充奖品文字
drawNineText(canvas);
}
/**
* 在每个矩形中填充奖品图片
* left：The position of the left side of the bitmap being drawn
* top：The position of the top side of the bitmap being drawn
*/
private void drawNineBitmaps(final Canvas canvas) {
for (int i = 0; i < mRectFs.size(); i ) {
RectF rectF = mRectFs.get(i);
// 将图片设置在每个矩形中央
left = rectF.left mRectSize / 4;
top = rectF.top mRectSize / 4;
canvas.drawBitmap(Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), mLuckyPrizes[i]), mRectSize / 2, mRectSize / 2, false), left, top, null);
}
}
/**
* 在每个矩形中央填充文字，代替抽奖图片
* x：he x-coordinate of the origin of the text being drawn
* y：The y-coordinate of the baseline of the text being drawn
*/
private void drawNineText(Canvas canvas) {
for (int i = 0; i < mRectFs.size(); i ) {
RectF rectF = mRectFs.get(i);
float x = rectF.left mRectSize / 4; // 将文字设置在每个矩形中央
float y = rectF.top mRectSize - 20;
mPaint.setColor(Color.parseColor("#5e5448"));
mPaint.setStyle(Paint.Style.FILL);
mPaint.setTextSize(15); // unit px
if (i == mRectFs.size() - 1) {
canvas.drawText("", x, y, mPaint);
} else {
canvas.drawText(mPrizeDescription[i], x, y, mPaint);
}
}
}
/**
* 执行真正的绘制矩形操作
*/
private void drawNineRect(Canvas canvas) {
for (int x = 0; x < mRectFs.size(); x ) {
RectF rectF = mRectFs.get(x);
if (x == 8) {
mPaint.setColor(Color.WHITE);
} else {
if (mCurrentPosition == x) {
mPaint.setColor(Color.parseColor("#edcea9"));
} else {
mPaint.setColor(mItemColor[x % 2]); // 标记当前转盘经过的位置
}
}
canvas.drawRect(rectF, mPaint);
}
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
mShouldStartFlag = mRectFs.get(8).contains(event.getX(), event.getY());
return true;
}
if (event.getAction() == MotionEvent.ACTION_UP) {
if (mShouldStartFlag) {
if (mRectFs.get(8).contains(event.getX(), event.getY())) {
// mLuckAnimationEndListener.onClickLuck();
startAnim(); // 判断只有手指落下和抬起都在中间的矩形内时才开始执行动画抽奖
}
mShouldStartFlag = false;
}
}
return super.onTouchEvent(event);
}
private void startAnim() {
if (!mShouldStartNextTurn) {
return;
}
Random random = new Random();
setLuckNum(random.nextInt(8)); // 生成 [0,8) 的随机整数
ValueAnimator animator = ValueAnimator.ofInt(mStartLuckPosition, mRepeatCount * 8 mLuckNum)
.setDuration(5000);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
final int position = (int) animation.getAnimatedValue();
setCurrentPosition(position % 8);
mShouldStartNextTurn = false;
}
});
animator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mShouldStartNextTurn = true;
mStartLuckPosition = mLuckNum;
//最终选中的位置
if (mLuckAnimationEndListener != null) {
mLuckAnimationEndListener.onLuckAnimationEnd(mCurrentPosition,
mPrizeDescription[mCurrentPosition]);
}
}
});
animator.start();
}
private void setCurrentPosition(int position) {
mCurrentPosition = position;
invalidate(); // 强制刷新，在 UI 线程回调 onDraw()
}
public void setBitmap(Bitmap[] bitmaps1, String[] name, String[] strings) {
bitmaps = bitmaps1;
luckyName = name;
id = strings;
invalidate();
}
/**
* 选中id
*
* @param datas
*/
public void setSelectId(int datas) {
String selectId = datas "";
if (id != null && id.length != 0) {
for (int i = 0; i < id.length; i ) {
if (id[i].equals(selectId)) {
selectPos = i;
}
}
}
startAnim();
}
/**
* 用于抽奖结果回调
*/
public interface OnLuckAnimationEndListener {
void onLuckAnimationEnd(int pos, String msg);
}
}3.主界面布局文件
代码语言：txt复制<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fff"
tools:context=".MainActivity">
<com.showly.luckyactivity.view.LuckyView
android:id="@ id/lucky_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="50dp"/>
</RelativeLayout>4.主程序
这里比较简单，就是输出抽奖结果
代码语言：txt复制public class MainActivity extends AppCompatActivity {
private LuckyView luckyView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initData();
initListener();
}
private void initView() {
luckyView = findViewById(R.id.lucky_view);
}
private void initData() {
}
private void initListener() {
luckyView.setLuckAnimationEndListener(new LuckyView.OnLuckAnimationEndListener() {
@Override
public void onLuckAnimationEnd(int pos, String msg) {
//打印抽奖结果
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_SHORT).show();
}
});
}
}5，总结
实现九宫格抽奖重点在自定义View的处理，代码中有文字解析，这里就不重复说明了，还有这里抽奖展示的图片及文字是固定的，如果需要动态设置图片及文字数据的话，可以自己更改自定义控件中的逻辑。
需要Demo源码的童鞋可以在底部的公众号回复："九宫格抽奖"即可获取。
小编整理了一份Android电子书籍，需要的童鞋关注公众号回复："e_books" 即可获取哦！
在这里插入图片描述欢迎关注公众号(longxuanzhigu)，获得更多福利、精彩内容哦！
在这里插入图片描述
