android 自定义八边形进度条

自定义八边形动画效果图如下
绘制步骤：
1.先绘制橙色底部八边形实心
2.黑色画笔绘制第二层，让最外层显示一条线条宽度即可
3.再用黄色画笔绘制黄色部分
4.使用渐变画笔根据当前进度绘制覆盖黄色部分
5.使用黑色画笔根据当前进度绘制刻度条
6.黑色画笔绘制第三层留出黄色部分的宽度

完整代码

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RadialGradient;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.view.View;public class EightView extends View {private Paint mPaint;private Paint roundPaint;private Paint bgPaint;private float mR, mCx, mCy,mR1,mR2;private static final int mN = 8;private static final float DEGREES_UNIT = 360 / mN; //正N边形每个角  360/mN能整除private int width = 0;private int height = 0;//外部描边色：#d06d38private int[] colors = new int[]{Color.parseColor("#e3682f"),Color.parseColor("#e3682f"),Color.parseColor("#e59f3a"),Color.parseColor("#e59f3a"),};public EightView(Context context) {this(context, null);}public EightView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public EightView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);//   PorterDuffXfermode porterDuffXfermode = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);//绘制8边形外环mPaint = new Paint();mPaint.setColor(Color.parseColor("#e3682f"));mPaint.setStyle(Paint.Style.STROKE);mPaint.setStrokeCap(Paint.Cap.ROUND); // 设置转弯处为圆角// 当绘图样式为 STROKE 时，该方法用于指定线条连接处的拐角样式，能使绘制的图形更加平滑mPaint.setStrokeJoin(Paint.Join.ROUND);mPaint.setStrokeWidth(50F);//  mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST));mPaint.setAntiAlias(true);//绘制刻度圆，然后进行裁剪，按照外环的大小roundPaint=new Paint();roundPaint.setStyle(Paint.Style.FILL);roundPaint.setAntiAlias(true);roundPaint.setStrokeWidth(8);//  roundPaint.setXfermode(porterDuffXfermode);//绘制黑色背景，bgPaintbgPaint=new Paint();bgPaint.setColor(Color.YELLOW);bgPaint.setStyle(Paint.Style.FILL);bgPaint.setAntiAlias(true);//    bgPaint.setXfermode(porterDuffXfermode);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);width = getSize(widthMeasureSpec);height = getSize(heightMeasureSpec);if (width < height) {height = width;} else {width = height;}setMeasuredDimension(width, height);}private int getSize(int measureSpec) {int mySize = 100;int mode = MeasureSpec.getMode(measureSpec);int size = MeasureSpec.getSize(measureSpec);switch (mode) {case MeasureSpec.UNSPECIFIED: {//如果没有指定大小:就设置为默认大小mySize = 100;break;}case MeasureSpec.AT_MOST: //如果测里模式是最大取值为size,我们将大小取最大值,你也可以取其他值case MeasureSpec.EXACTLY: {//如果是固定的大小,那就不要去改变它mySize = size;break;}}return mySize;}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);float mW = getMeasuredWidth();float mH = getMeasuredHeight();if (mW < mH) {mH = mW;} else {mW = mH;}//----mCx-230.0---mCy-230.0---mR-172.5mCx = mW / 2;mCy = mH / 2;//mCx和mCy中的较小者mR = Math.min(mCx, mCy) / 4 * 3;mR1 = mW/7*3;mR2=mR1-5;}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);canvas.rotate(23, mCx, mCy);
//        canvas.rotate(-45, mCx, mCy);canvas.drawColor(bgColor);mPaint.setColor(Color.parseColor("#e3682f"));float d1 = (float) (2 * mR1 * Math.sin(Math.toRadians(DEGREES_UNIT / 2)));float c1 = mCy - mR1;float y1 = (d1 * d1 + mCy * mCy - c1 * c1 - mR1 * mR1) / (2 * (mCy - c1));float x1 = (float) (mCx + Math.sqrt(-1 * c1 * c1 + 2 * c1 * y1 + d1 * d1 - y1 * y1));for (int i = 0; i < 8; i++) {canvas.save();canvas.rotate(DEGREES_UNIT * i, mCx, mCy);canvas.drawLine(mCx, c1, x1, y1, mPaint);canvas.restore();}mPaint.setColor(bgColor);float d2 = (float) (2 * mR2 * Math.sin(Math.toRadians(DEGREES_UNIT / 2)));float c2 = mCy - mR2;float y2 = (d2 * d2 + mCy * mCy - c2 * c2 - mR2 * mR2) / (2 * (mCy - c2));float x2 = (float) (mCx + Math.sqrt(-1 * c2 * c2 + 2 * c2 * y2 + d2 * d2 - y2 * y2));for (int i = 0; i < 8; i++) {canvas.save();canvas.rotate(DEGREES_UNIT * i, mCx, mCy);// canvas.drawLine(mCx, mCy, mCx, c, mPaint);//中间的连接线canvas.drawLine(mCx, c2, x2, y2, mPaint);canvas.restore();}//离屏绘制int layer1 = canvas.saveLayer(0, 0, width, height, mPaint);int layer2 = canvas.saveLayer(0, 0, width, height, bgPaint);int layer3 = canvas.saveLayer(0, 0, width, height, roundPaint);mPaint.setColor(Color.parseColor("#e59f3a"));float d = (float) (2 * mR * Math.sin(Math.toRadians(DEGREES_UNIT / 2)));float c = mCy - mR;float y = (d * d + mCy * mCy - c * c - mR * mR) / (2 * (mCy - c));float x = (float) (mCx + Math.sqrt(-1 * c * c + 2 * c * y + d * d - y * y));for (int i = 0; i < 8; i++) {canvas.save();canvas.rotate(DEGREES_UNIT * i, mCx, mCy);canvas.drawLine(mCx, c, x, y, mPaint);canvas.restore();}if (gradient==null){gradient =new RadialGradient(mCx,mCy, mCx/5,colors,null, Shader.TileMode.MIRROR);}bgPaint.setShader(gradient);/*** left–矩形左侧的X坐标* top–矩形顶部的Y坐标* right–矩形右侧的X坐标* bottom–矩形底部的Y坐标*/if (rectF==null){rectF = new RectF(0, 0, width, height);}bgPaint.setXfermode(mode);canvas.drawArc(rectF, 67, indexCircle, true, bgPaint);//底部圆//最后将画笔去除XfermodebgPaint.setXfermode(null);//绘制刻度线canvas.translate(width / 2, height / 2);roundPaint.setXfermode(mode);roundPaint.setColor(bgColor);//90度12根，360度48根 270度36  //90度8根，360度30根int index=indexCircle*46/360;for (int i = 0; i < index; i++) {//共48等分，根据绘制的角度更改canvas.save();//画布保存int degress=i * 8+67;if (degress>360){degress=degress-360;}canvas.rotate(degress);//绘制图标的旋转360 + i * 36
//            int alpha = (int) ((i / 60f * 255 + circleAlpha) % 255);
//            mPaint.setAlpha(alpha);//设置画笔的透明度[0-255]，0是完全透明，255是完全不透明canvas.translate(width/2-mCircleWidth, 0);//绘图坐标的平移。canvas.drawLine(0, 0, mCircleWidth, 0, roundPaint);//绘制线.drawLine,drawLines绘制多条线canvas.restore();//合并保存后的图层}//最后将画笔去除XfermoderoundPaint.setXfermode(null);//恢复图层canvas.restoreToCount(layer1);canvas.restoreToCount(layer2);canvas.restoreToCount(layer3);}private  RadialGradient gradient;private  RectF rectF;private PorterDuffXfermode mode=new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP);private int mCircleWidth = 120;//圆弧的长度private int indexCircle=0;private int bgColor=Color.BLACK;public void setBgColor(int BgColor){bgColor=BgColor;}public void setAngle(int mStepNum) {mStepNum=360-mStepNum;if (mStepNum > 360) {mStepNum = 360;}if (mStepNum < 0) {mStepNum = 0;}this.indexCircle = mStepNum;invalidate();}
}