先看下iOS的芝麻信用分截图

这是我做的效果，还是有点差距的

支付宝9.9版本芝麻信用分的实现

首先初始化各种画笔,默认的size，padding，小圆点.

(因为实在找不到原版芝麻信用的带点模糊效果的小圆点,所以只好用这个代替)

//View的默认大小 defaultSize = dp2px(250); //默认Padding大小 arcDistance = dp2px(14); //外层圆环画笔 mMiddleArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mMiddleArcPaint.setStrokeWidth(8); mMiddleArcPaint.setColor(Color.WHITE); mMiddleArcPaint.setStyle(Paint.Style.STROKE); mMiddleArcPaint.setAlpha(80); //内层圆环画笔 mInnerArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mInnerArcPaint.setStrokeWidth(30); mInnerArcPaint.setColor(Color.WHITE); mInnerArcPaint.setAlpha(80); mInnerArcPaint.setStyle(Paint.Style.STROKE); //正中间字体画笔 mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mTextPaint.setColor(Color.WHITE); mTextPaint.setTextAlign(Paint.Align.CENTER); //圆环大刻度画笔 mCalibrationPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mCalibrationPaint.setStrokeWidth(4); mCalibrationPaint.setStyle(Paint.Style.STROKE); mCalibrationPaint.setColor(Color.WHITE); mCalibrationPaint.setAlpha(120); //圆环小刻度画笔 mSmallCalibrationPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mSmallCalibrationPaint.setStrokeWidth(1); mSmallCalibrationPaint.setStyle(Paint.Style.STROKE); mSmallCalibrationPaint.setColor(Color.WHITE); mSmallCalibrationPaint.setAlpha(130); //圆环刻度文本画笔 mCalibrationTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mCalibrationTextPaint.setTextSize(30); mCalibrationTextPaint.setColor(Color.WHITE); //外层进度画笔 mArcProgressPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mArcProgressPaint.setStrokeWidth(8); mArcProgressPaint.setColor(Color.WHITE); mArcProgressPaint.setStyle(Paint.Style.STROKE); mArcProgressPaint.setStrokeCap(Paint.Cap.ROUND); //外层圆环上小圆点Bitmap画笔 mBitmapPaint = new Paint(); mBitmapPaint.setStyle(Paint.Style.FILL); mBitmapPaint.setAntiAlias(true); //初始化小圆点图片 bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_circle); //当前点的实际位置 pos = new float[2]; //当前点的tangent值 tan = new float[2]; matrix = new Matrix();

代码很简单,就是各种初始化,往下看.

View的测量,主要在给设置warp_content时候给定一个默认宽高值.

@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){ setMeasuredDimension(resolveMeasure(widthMeasureSpec, defaultSize), resolveMeasure(heightMeasureSpec, defaultSize));} //根据传入的值进行测量 public int resolveMeasure(int measureSpec, int defaultSize){ int result = 0; int specSize = MeasureSpec.getSize(measureSpec); switch (MeasureSpec.getMode(measureSpec)) { case MeasureSpec.UNSPECIFIED: result = defaultSize; break; case MeasureSpec.AT_MOST: //设置warp_content时设置默认值 result = Math.min(specSize, defaultSize); break; case MeasureSpec.EXACTLY: //设置math_parent 和设置了固定宽高值 break; default: result = defaultSize; } return result;}

然后确定View的宽高后的回调方法.

@Override protected void onSizeChanged(int w, int h, int oldw, int oldh){ super.onSizeChanged(w, h, oldw, oldh); width = w; height = h; radius = width / 2; //外层圆环矩形 mMiddleRect = new RectF(defaultPadding, defaultPadding,width - defaultPadding, height - defaultPadding); //内层圆环矩形 mInnerRect = new RectF(defaultPadding + arcDistance, defaultPadding + arcDistance,width - defaultPadding - arcDistance, height - defaultPadding - arcDistance); // 外层进度矩形 mMiddleProgressRect = new RectF(defaultPadding, defaultPadding,width - defaultPadding, height - defaultPadding); }

这里就是初始化圆弧所需要的矩形实现,下边开始进行重点,绘制，

绘制外层的圆弧,很简单, 圆弧的起始角度,角度.

private void drawMiddleArc(Canvas canvas){ canvas.drawArc(mMiddleRect, mStartAngle, mEndAngle, false, mMiddleArcPaint); }

绘制内层圆弧

private void drawInnerArc(Canvas canvas){ canvas.drawArc(mInnerRect, mStartAngle, mEndAngle, false, mInnerArcPaint); }

绘制内层圆弧上的小刻度,画布旋转到圆弧左下角起点,计算出每条刻度线的起始点后,整个圆弧是210度,

每6角度绘制一条刻度线.

private void drawSmallCalibration(Canvas canvas){ //旋转画布 canvas.save(); canvas.rotate(-105, radius, radius); //计算刻度线的起点结束点 int startDst = (int) (defaultPadding + arcDistance - mInnerArcPaint.getStrokeWidth() / 2 - 1); int endDst = (int) (startDst + mInnerArcPaint.getStrokeWidth()); for (int i = 0; i <= 35; i++) { //每旋转6度绘制一个小刻度 canvas.drawLine(radius, startDst, radius, endDst, mSmallCalibrationPaint); canvas.rotate(6, radius, radius); } canvas.restore(); }

绘制内层圆弧上的大刻度,350, 550, 600,650, 700, 950，对应的信用分值,

一样旋转画布,计算刻度线的起始点,计算出每次旋转的角度,每35度旋转一次,依次绘制对应的大刻度线,

然后绘制对应的文本内容,使用paint的measureText方法测量出文本的长度,依次绘制对应的文本内容.

private void drawCalibrationAndText(Canvas canvas){ //旋转画布进行绘制对应的刻度 canvas.save(); canvas.rotate(-105, radius, radius); //计算刻度线的起点结束点 int startDst = (int) (defaultPadding + arcDistance - mInnerArcPaint.getStrokeWidth() / 2 - 1); int endDst = (int) (startDst + mInnerArcPaint.getStrokeWidth()); //刻度旋转的角度 int rotateAngle = 210 / 10; for (int i = 1; i < 12; i++) { if (i % 2 != 0) { canvas.drawLine(radius, startDst, radius, endDst, mCalibrationPaint); } // 测量文本的长度 float textLen = mCalibrationTextPaint.measureText(sesameStr[i - 1]); canvas.drawText(sesameStr[i - 1], radius - textLen / 2, endDst + 40, mCalibrationTextPaint); canvas.rotate(rotateAngle, radius, radius); } canvas.restore();}

绘制中间的信用分值,信用等级,评估时间等文本,这个比较简单,直接drawText,依次高低排列绘制即可.

private void drawCenterText(Canvas canvas){ //绘制Logo mTextPaint.setTextSize(30); canvas.drawText("BETA", radius, radius - 130, mTextPaint); //绘制信用分数 mTextPaint.setTextSize(200); mTextPaint.setStyle(Paint.Style.STROKE); canvas.drawText(String.valueOf(mMinNum), radius, radius + 70, mTextPaint); //绘制信用级别 mTextPaint.setTextSize(80); canvas.drawText(sesameLevel, radius, radius + 160, mTextPaint); //绘制评估时间 mTextPaint.setTextSize(30); canvas.drawText(evaluationTime, radius, radius + 205, mTextPaint); }

绘制最外层的进度,这里使用的Path添加要绘制的圆弧,因为需要去不断的计算坐标点,主要用到了PathMeasure这个类,将绘制的圆弧加入到path中,

当前点的实际位置

private float[] pos;

当前的tangent值

private float[] tan;

获取路径的终点的正切值和坐标，然后根据坐标点绘制小圆点

PathMeasure pathMeasure = new PathMeasure(path, false); pathMeasure.getPosTan(pathMeasure.getLength() * 1, pos, tan);

private void drawRingProgress(Canvas canvas){ Path path = new Path(); path.addArc(mMiddleProgressRect, mStartAngle, mCurrentAngle); PathMeasure pathMeasure = new PathMeasure(path, false); pathMeasure.getPosTan(pathMeasure.getLength() * 1, pos, tan); matrix.reset(); matrix.postTranslate(pos[0] - bitmap.getWidth() / 2, pos[1] - bitmap.getHeight() / 2); canvas.drawPath(path, mArcProgressPaint); //起始角度不为0时候才进行绘制小圆点 if (mCurrentAngle == 0) return; canvas.drawBitmap(bitmap, matrix, mBitmapPaint); mBitmapPaint.setColor(Color.WHITE); canvas.drawCircle(pos[0], pos[1], 8, mBitmapPaint); }

好了,到这里所有绘制完毕了,接下来让圆弧进度条动起来吧,使用ValueAnimator,进度条动画定义了圆弧进度条的开始角度mCurrentAngle,圆弧角度mTotalAngle,数值动画定义了初始化minNum=0，maxNum根据传入的数值进行计算.

public void startAnim(){ ValueAnimator mAngleAnim = ValueAnimator.ofFloat(mCurrentAngle, mTotalAngle); mAngleAnim.setInterpolator(new AccelerateDecelerateInterpolator()); mAngleAnim.setDuration(3000); mAngleAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener(){ @Override public void onAnimationUpdate(ValueAnimator valueAnimator){ mCurrentAngle = (float) valueAnimator.getAnimatedValue(); postInvalidate(); } }); mAngleAnim.start(); ValueAnimator mNumAnim = ValueAnimator.ofInt(mMinNum, mMaxNum); mNumAnim.setDuration(3000); mNumAnim.setInterpolator(new LinearInterpolator()); mNumAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator){ mMinNum = (int) valueAnimator.getAnimatedValue(); postInvalidate(); } }); mNumAnim.start();}

最后根据传入的信用分值计算圆弧进度条所到的角度.

public void setSesameValues(int values){ if (values <= 350){ mMaxNum = values; mTotalAngle = 0f; sesameLevel = "信用较差"; evaluationTime = "评估时间:" + getCurrentTime(); } else if (values <= 550){ mMaxNum = values; mTotalAngle = (values - 350) * 80 / 400f + 2; sesameLevel = "信用较差"; evaluationTime = "评估时间:" + getCurrentTime(); } else if (values <= 700) { mMaxNum = values; if (values > 550 && values <= 600){ sesameLevel = "信用中等"; } else if (values > 600 && values <= 650){ sesameLevel = "信用良好"; } else { sesameLevel = "信用优秀"; } mTotalAngle = (values - 550) * 120 / 150f + 43; evaluationTime = "评估时间:" + getCurrentTime(); } else if (values <= 950){ mMaxNum = values; mTotalAngle = (values - 700) * 40 / 250f + 170; sesameLevel = "信用极好"; evaluationTime = "评估时间:" + getCurrentTime(); } else{ mTotalAngle = 240f; } startAnim(); }

总结

这篇文章只分析了新版的实现过程，旧版的的实现思路也差不多，代码也不复杂。希望这篇文章对大家开发Android能有所帮助，如果有疑问可以留言交流。