Android自定義View仿支付寶芝麻信用分儀表盤

先看下iOS的芝麻信用分截圖

這是我做的效果，還是有點差距的

支付寶9.9版本芝麻信用分的實現

首先初始化各種畫筆,默認的size，padding，小圓點.

(因為實在找不到原版芝麻信用的帶點模糊效果的小圓點,所以只好用這個代替)

//View的默認大小
defaultSize = dp2px(250);
//默認Padding大小
arcDistance = dp2px(14);

//外層圓環畫筆
mMiddleArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mMiddleArcPaint.setStrokeWidth(8);
mMiddleArcPaint.setColor(Color.WHITE);
mMiddleArcPaint.setStyle(Paint.Style.STROKE);
mMiddleArcPaint.setAlpha(80);

//內層圓環畫筆
mInnerArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mInnerArcPaint.setStrokeWidth(30);
mInnerArcPaint.setColor(Color.WHITE);
mInnerArcPaint.setAlpha(80);
mInnerArcPaint.setStyle(Paint.Style.STROKE);

//正中間字體畫筆
mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mTextPaint.setColor(Color.WHITE);
mTextPaint.setTextAlign(Paint.Align.CENTER);

//圓環大刻度畫筆
mCalibrationPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mCalibrationPaint.setStrokeWidth(4);
mCalibrationPaint.setStyle(Paint.Style.STROKE);
mCalibrationPaint.setColor(Color.WHITE);
mCalibrationPaint.setAlpha(120);

//圓環小刻度畫筆
mSmallCalibrationPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mSmallCalibrationPaint.setStrokeWidth(1);
mSmallCalibrationPaint.setStyle(Paint.Style.STROKE);
mSmallCalibrationPaint.setColor(Color.WHITE);
mSmallCalibrationPaint.setAlpha(130);

//圓環刻度文本畫筆
mCalibrationTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mCalibrationTextPaint.setTextSize(30);
mCalibrationTextPaint.setColor(Color.WHITE);

//外層進度畫筆
mArcProgressPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mArcProgressPaint.setStrokeWidth(8);
mArcProgressPaint.setColor(Color.WHITE);
mArcProgressPaint.setStyle(Paint.Style.STROKE);
mArcProgressPaint.setStrokeCap(Paint.Cap.ROUND);

//外層圓環上小圓點Bitmap畫筆
mBitmapPaint = new Paint();
mBitmapPaint.setStyle(Paint.Style.FILL);
mBitmapPaint.setAntiAlias(true);

//初始化小圓點圖片
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_circle);
//當前點的實際位置
pos = new float[2];
//當前點的tangent值
tan = new float[2];
matrix = new Matrix();

代碼很簡單,就是各種初始化,往下看.

View的測量,主要在給設置warp_content時候給定一個默認寬高值.

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){ 
setMeasuredDimension(resolveMeasure(widthMeasureSpec, defaultSize), 
  resolveMeasure(heightMeasureSpec, defaultSize));}

//根據傳入的值進行測量
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:   
 //設置warp_content時設置默認值   
 result = Math.min(specSize, defaultSize);   
 break;  
 case MeasureSpec.EXACTLY:   
 //設置math_parent 和設置了固定寬高值   
 break;  
 default:   
 result = defaultSize; 
 } 
 return result;}

然後確定View的寬高後的回調方法.

@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; 
//外層圓環矩形
 mMiddleRect = new RectF(defaultPadding, defaultPadding,width - defaultPadding, height - defaultPadding); 
//內層圓環矩形
 mInnerRect = new RectF(defaultPadding + arcDistance, defaultPadding + arcDistance,width - defaultPadding - arcDistance, height - defaultPadding - arcDistance); 
// 外層進度矩形
 mMiddleProgressRect = new RectF(defaultPadding, defaultPadding,width - defaultPadding, height - defaultPadding);
}

這裡就是初始化圓弧所需要的矩形實現,下邊開始進行重點,繪制，

繪制外層的圓弧,很簡單, 圓弧的起始角度,角度.

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

繪制內層圓弧

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

繪制內層圓弧上的小刻度,畫布旋轉到圓弧左下角起點,計算出每條刻度線的起始點後,整個圓弧是210度,

每6角度繪制一條刻度線.

private void drawSmallCalibration(Canvas canvas){ 
 //旋轉畫布 
 canvas.save(); 
 canvas.rotate(-105, radius, radius); 
 //計算刻度線的起點結束點 
 int startDst = (int) (defaultPadding + arcDistance - mInnerArcPaint.getStrokeWidth() / 2 - 1); 
 int endDst = (int) (startDst + mInnerArcPaint.getStrokeWidth()); 
 for (int i = 0; i <= 35; i++) {  
 //每旋轉6度繪制一個小刻度  
 canvas.drawLine(radius, startDst, radius, endDst, mSmallCalibrationPaint);  
 canvas.rotate(6, radius, radius); 
} 
canvas.restore();
}

繪制內層圓弧上的大刻度,350, 550, 600,650, 700, 950，對應的信用分值,

一樣旋轉畫布,計算刻度線的起始點,計算出每次旋轉的角度,每35度旋轉一次,依次繪制對應的大刻度線,

然後繪制對應的文本內容,使用paint的measureText方法測量出文本的長度,依次繪制對應的文本內容.

private void drawCalibrationAndText(Canvas canvas){ 
 //旋轉畫布進行繪制對應的刻度 
 canvas.save(); 
 canvas.rotate(-105, radius, radius); 
 //計算刻度線的起點結束點 
 int startDst = (int) (defaultPadding + arcDistance - mInnerArcPaint.getStrokeWidth() / 2 - 1); 
 int endDst = (int) (startDst + mInnerArcPaint.getStrokeWidth()); 
 //刻度旋轉的角度 
 int rotateAngle = 210 / 10; 
 for (int i = 1; i < 12; i++) {  
 if (i % 2 != 0)  
 {   
 canvas.drawLine(radius, startDst, radius, endDst, mCalibrationPaint);  
 }  
 // 測量文本的長度  
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();}

繪制中間的信用分值,信用等級,評估時間等文本,這個比較簡單,直接drawText,依次高低排列繪制即可.

private void drawCenterText(Canvas canvas){ 
 //繪制Logo 
 mTextPaint.setTextSize(30); 
 canvas.drawText("BETA", radius, radius - 130, mTextPaint); 
 //繪制信用分數 
 mTextPaint.setTextSize(200); 
 mTextPaint.setStyle(Paint.Style.STROKE); 
 canvas.drawText(String.valueOf(mMinNum), radius, radius + 70, mTextPaint); 
 //繪制信用級別 
 mTextPaint.setTextSize(80); 
 canvas.drawText(sesameLevel, radius, radius + 160, mTextPaint); 
 //繪制評估時間 
 mTextPaint.setTextSize(30); 
 canvas.drawText(evaluationTime, radius, radius + 205, mTextPaint);
}

繪制最外層的進度,這裡使用的Path添加要繪制的圓弧,因為需要去不斷的計算坐標點,主要用到了PathMeasure這個類,將繪制的圓弧加入到path中,

當前點的實際位置

private float[] pos;

當前的tangent值

private float[] tan;

獲取路徑的終點的正切值和坐標，然後根據坐標點繪制小圓點

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); 
 //起始角度不為0時候才進行繪制小圓點 
 if (mCurrentAngle == 0)  
  return; 
 canvas.drawBitmap(bitmap, matrix, mBitmapPaint); 
 mBitmapPaint.setColor(Color.WHITE); 
 canvas.drawCircle(pos[0], pos[1], 8, mBitmapPaint);
}

好了,到這裡所有繪制完畢了,接下來讓圓弧進度條動起來吧,使用ValueAnimator,進度條動畫定義了圓弧進度條的開始角度mCurrentAngle,圓弧角度mTotalAngle,數值動畫定義了初始化minNum=0，maxNum根據傳入的數值進行計算.

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();}

最後根據傳入的信用分值計算圓弧進度條所到的角度.

public void setSesameValues(int values){ 
 if (values <= 350){  
 mMaxNum = values;  
 mTotalAngle = 0f;  
 sesameLevel = "信用較差";  
 evaluationTime = "評估時間:" + getCurrentTime(); 
 } else if (values <= 550){  
 mMaxNum = values;  
 mTotalAngle = (values - 350) * 80 / 400f + 2;  
 sesameLevel = "信用較差";  
 evaluationTime = "評估時間:" + 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 = "信用優秀";  
 }  
 mTotalAngle = (values - 550) * 120 / 150f + 43;  
 evaluationTime = "評估時間:" + getCurrentTime(); 
 } else if (values <= 950){  
 mMaxNum = values;  
 mTotalAngle = (values - 700) * 40 / 250f + 170;  
 sesameLevel = "信用極好";  
 evaluationTime = "評估時間:" + getCurrentTime(); 
 } else{  
 mTotalAngle = 240f; 
 } 
 startAnim();
}

總結

這篇文章只分析了新版的實現過程，舊版的的實現思路也差不多，代碼也不復雜。希望這篇文章對大家開發Android能有所幫助，如果有疑問可以留言交流。