private SurfaceHolder mSurfaceHolder;private Canvas    mCanvas;

public SurfaceViewTemplate(Context context,AttributeSet attrs) {  super(context, attrs);  //初始化  mSurfaceHolder = getHolder();  mSurfaceHolder.addCallback(this);  //設(shè)置可獲得焦點(diǎn)  setFocusable(true);  setFocusableInTouchMode(true);  //這是常亮  setKeepScreenOn(true);}

 @Overridepublic void surfaceCreated(SurfaceHolder surfaceHolder) {  //surface創(chuàng)建的時候  mThread = new Thread(this);  //創(chuàng)建的時候就開啟線程  isRunning = true;  mThread.start();}@Overridepublic void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {  //變化的時候}@Overridepublic void surfaceDestroyed(SurfaceHolder surfaceHolder) {  //銷毀的時候 關(guān)閉線程  isRunning = false;}

 @Overridepublic void run() {  //在子線程中不斷的繪制  while (isRunning) {    draw();  }}private void draw() {  try {    mCanvas = mSurfaceHolder.lockCanvas();    if (null != mCanvas) {  //避免執(zhí)行到這里的時候程序已經(jīng)退出 surfaceView已經(jīng)銷毀那么獲取到canvas為null    }  } catch (Exception e) {    //異常可以不必處理  } finally {    //一定要釋放canvas避免泄露    mSurfaceHolder.unlockCanvasAndPost(mCanvas);  }}

@Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    super.onMeasure(widthMeasureSpec, heightMeasureSpec);    //直接控制Span為正方形    int width = Math.min(getMeasuredWidth(), getMeasuredHeight());    mPadding = getPaddingLeft();    //直徑    mRadius = width - mPadding * 2;    //設(shè)置中心點(diǎn)    mCenter = width / 2;    //設(shè)置成正方形    setMeasuredDimension(width, width);  }

public void surfaceCreated(SurfaceHolder surfaceHolder) {    //初始化繪制Span的畫筆    mSpanPaint = new Paint();    mSpanPaint.setAntiAlias(true);    mSpanPaint.setDither(true);    //初始化繪制文本的畫筆    mTextPaint = new Paint();    mTextPaint.setTextSize(mTextSize);    mTextPaint.setColor(0Xffa58453);    //繪制圓環(huán)的畫筆    mCirclePaint = new Paint();    mCirclePaint.setAntiAlias(true);    mCirclePaint.setColor(0xffdfc89c);    //初始化Span的范圍    mRectRange = new RectF(mPadding, mPadding, mPadding + mRadius, mPadding + mRadius);    mRectCircleRange = new RectF(mPadding * 3 / 2, mPadding * 3 / 2, getMeasuredWidth() - mPadding * 3 / 2, getMeasuredWidth() - mPadding * 3 / 2);    //初始化bitmap    mImgIconBitmap = new Bitmap[mSpanCount];    //將獎項(xiàng)的icon存儲為Bitmap    for (int i = 0; i < mSpanCount; i++) {      mImgIconBitmap[i] = BitmapFactory.decodeResource(getResources(), mPrizeIcon[i]);    }    //surface創(chuàng)建的時候    mThread = new Thread(this);    //創(chuàng)建的時候就開啟線程    isRunning = true;    mThread.start();  }

 @Override  public void run() {    //在子線程中不斷的繪制    while (isRunning) {      //保證繪制不低于50毫秒 優(yōu)化性能      long start = SystemClock.currentThreadTimeMillis();      draw();      long end = SystemClock.currentThreadTimeMillis();      if ((end - start) < 50) {        //休眠到50毫秒        SystemClock.sleep(50 - (end - start));      }    }  }

 try {    mCanvas = mSurfaceHolder.lockCanvas();    if (null != mCanvas) {      //避免執(zhí)行到這里的時候程序已經(jīng)退出 surfaceView已經(jīng)銷毀那么獲取到canvas為null      //繪制背景      drawBg();      //繪制圓環(huán)      mCanvas.drawCircle(mCenter, mCenter, mRadius / 2 + mPadding / 20, mCirclePaint);      drawSpan();    }  } catch (Exception e) {    //異常可以不必處理  } finally {    //一定要釋放canvas避免泄露    mSurfaceHolder.unlockCanvasAndPost(mCanvas);  }

//繪制背景  private void drawBg() {    //背景設(shè)置為白色    mCanvas.drawColor(0xffffffff);    mCanvas.drawBitmap(mSpanBackground, null, new RectF(mPadding / 2, mPadding / 2, getMeasuredWidth() - mPadding / 2, getMeasuredHeight() - mPadding / 2), mSpanPaint);  }

  mSpanBackground背景圖片  new RectF(mPadding / 2, mPadding / 2, getMeasuredWidth() - mPadding / 2, getMeasuredHeight() - mPadding / 2)  //限制背景在一個矩形范圍之類 

mCanvas.drawCircle(mCenter, mCenter, mRadius / 2 + mPadding / 20, mCirclePaint); 

//定義一個變量臨時記錄開始轉(zhuǎn)動的角度float tempAngle = mStartSpanAngle;//每個盤塊所占的角度 CIRCLE_ANGLE = 360float sweepAngle = CIRCLE_ANGLE / mSpanCount;//循環(huán)繪制八個板塊  for (int i = 0; i < mSpanCount; i++) {    //設(shè)置每個盤塊畫筆的顏色    mSpanPaint.setColor(mSpanColor[i]);    //繪制扇形盤塊，第四個參數(shù)為true就是扇形否則就是弧形    mCanvas.drawArc(mRectCircleRange, tempAngle, sweepAngle, true, mSpanPaint);    //繪制文字    drawText(tempAngle, sweepAngle, mPrizeName[i]);    //繪制獎項(xiàng)Icon    drawPrizeIcon(tempAngle, mImgIconBitmap[i]);      //改變角度      tempAngle += sweepAngle;    }

private void drawText(float tempAngle, float sweepAngle, String text) {  //繪制有弧度的文字 根據(jù)path繪制文字的路徑  Path path = new Path();  path.addArc(mRectRange, tempAngle, sweepAngle);  //讓文字水平居中 那繪制文字的起點(diǎn)位子就是 弧度的一半 - 文字的一半  float textWidth = mTextPaint.measureText(text);  float hOval = (float) ((mRadius * Math.PI / mSpanCount / 2) - (textWidth / 2));  float vOval = mRadius / 15;//豎直偏移量可以自定義  mCanvas.drawTextOnPath(text, path, hOval, vOval, mTextPaint); //第三個四個參數(shù)是豎直和水平偏移量}

private void drawPrizeIcon(float tempAngle, Bitmap bitmap) {  //圖片的大小設(shè)置成直徑的1/8  int iconWidth = mRadius / 20;  //根據(jù)角度計(jì)算icon中心點(diǎn)  //角度計(jì)算 1度 == Math.PI / 180  double angle = (tempAngle + CIRCLE_ANGLE / mSpanCount / 2) * Math.PI / 180;  //根據(jù)三角函數(shù)，計(jì)算中心點(diǎn)(x,y)  int x = (int) (mCenter + mRadius / 4 * Math.cos(angle));  int y = (int) (mCenter + mRadius / 4 * Math.sin(angle));  //定義一個矩形 限制icon位置  RectF rectF = new RectF(x - iconWidth, y - iconWidth, x + iconWidth, y + iconWidth);  mCanvas.drawBitmap(bitmap, null, rectF, null);}

 mStartSpanAngle += mSpeed;//mSpeed的數(shù)值控制轉(zhuǎn)動的速度   //聲明的一個結(jié)束標(biāo)志  if (isSpanEnd) {    mSpeed -= 1;  }  if (mSpeed <= 0) {    //停止旋轉(zhuǎn)了    mSpeed = 0;    isSpanEnd = false;    //定義一個回調(diào)，監(jiān)控轉(zhuǎn)盤停止轉(zhuǎn)動   mSpanRollListener.onSpanRollListener(mSpeed);  }

//抽獎轉(zhuǎn)盤重點(diǎn)就在這里，根據(jù)自己傳入的index控制抽到的獎品public void luckyStart(int index) {  //根據(jù)index控制停留的位置 angle 是每個獎品所占的角度范圍  float angle = CIRCLE_ANGLE / mSpanCount;  //計(jì)算指針停留在某個index下的角度范圍HALF_CIRCLE_ANGLE=180度  float from = HALF_CIRCLE_ANGLE - (index - 1) * angle;  float end = from + angle;  //設(shè)置需要停下來的時候轉(zhuǎn)動的距離 保證每次不停留的某個index下的同一個位置  float targetFrom = 4 * CIRCLE_ANGLE + from;  float targetEnd = 4 * CIRCLE_ANGLE + end;//最終停下來的位置在from-end之間，4 * CIRCLE_ANGLE 自定義要多轉(zhuǎn)幾圈  //計(jì)算要停留下來的時候速度的范圍，這里注意：涉及到等差數(shù)列的公式，因?yàn)樯婕暗阶屴D(zhuǎn)盤停止轉(zhuǎn)動是使mSpeed-=1；所以它是從 vFrom--0等差遞減的一個過程，所以可以算出來vFrom，同理計(jì)算出vEnd  float vFrom = (float) ((Math.sqrt(1 + 8 * targetFrom) - 1) / 2);  float vEnd = (float) ((Math.sqrt(1 + 8 * targetEnd) - 1) / 2);  //在點(diǎn)擊開始轉(zhuǎn)動的時候 傳遞進(jìn)來的index值就已經(jīng)決定停留在那一項(xiàng)上面了  mSpeed = vFrom + Math.random() * (vEnd - vFrom);  isSpanEnd = false;}

 public void luckStop() {  //在停止轉(zhuǎn)盤的時候強(qiáng)制吧開始角度賦值為0 因?yàn)榭刂仆Ａ糁付ㄎ恢玫慕嵌扔?jì)算是根據(jù)開始角度為0計(jì)算的  mStartSpanAngle = 0;  isSpanEnd = true;}