效果如下：

主要代码

CircularProgressView.java

public class CircularProgressView extends View {private Paint mBackPaint, mProgPaint;   // 绘制画笔private RectF mRectF;       // 绘制区域private int[] mColorArray;  // 圆环渐变色private int mProgress;      // 圆环进度(0-100)/*** 绘制弧线的画笔*/private Paint progressPaint;/*** 圆弧圆心位置*/private int centerX, centerY;/*** 圆弧的半径*/private int circleRadius;public CircularProgressView(Context context) {this(context, null);}public CircularProgressView(Context context, @Nullable AttributeSet attrs) {this(context, attrs, 0);}public CircularProgressView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);@SuppressLint("Recycle")TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CircularProgressView);// 初始化背景圆环画笔mBackPaint = new Paint();mBackPaint.setStyle(Paint.Style.STROKE);    // 只描边，不填充mBackPaint.setStrokeCap(Paint.Cap.ROUND);   // 设置圆角mBackPaint.setAntiAlias(true);              // 设置抗锯齿mBackPaint.setDither(true);                 // 设置抖动mBackPaint.setStrokeWidth(typedArray.getDimension(R.styleable.CircularProgressView_backWidth, 5));mBackPaint.setColor(typedArray.getColor(R.styleable.CircularProgressView_progbgColor, Color.LTGRAY));// 初始化进度圆环画笔mProgPaint = new Paint();mProgPaint.setStyle(Paint.Style.STROKE);    // 只描边，不填充mProgPaint.setStrokeCap(Paint.Cap.ROUND);   // 设置圆角mProgPaint.setAntiAlias(true);              // 设置抗锯齿mProgPaint.setDither(true);                 // 设置抖动mProgPaint.setStrokeWidth(typedArray.getDimension(R.styleable.CircularProgressView_progWidth, 10));mProgPaint.setColor(typedArray.getColor(R.styleable.CircularProgressView_progColor, Color.BLUE));//初始化结束位置小圆点progressPaint = new Paint();progressPaint.setStyle(Paint.Style.FILL);    // 填充progressPaint.setStrokeCap(Paint.Cap.ROUND);   // 设置圆角progressPaint.setAntiAlias(true);              // 设置抗锯齿progressPaint.setDither(true);                 // 设置抖动progressPaint.setStrokeWidth(typedArray.getDimension(R.styleable.CircularProgressView_progWidth, 10));progressPaint.setColor(Color.WHITE);// 初始化进度圆环渐变色int startColor = typedArray.getColor(R.styleable.CircularProgressView_progStartColor, -1);int firstColor = typedArray.getColor(R.styleable.CircularProgressView_progFirstColor, -1);if (startColor != -1 && firstColor != -1) mColorArray = new int[]{startColor, firstColor};else mColorArray = null;// 初始化进度mProgress = typedArray.getInteger(R.styleable.CircularProgressView_progress, 0);typedArray.recycle();}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int viewWide = getMeasuredWidth() - getPaddingLeft() - getPaddingRight();int viewHigh = getMeasuredHeight() - getPaddingTop() - getPaddingBottom();int mRectLength = (int) ((viewWide > viewHigh ? viewHigh : viewWide) - (mBackPaint.getStrokeWidth() > mProgPaint.getStrokeWidth() ? mBackPaint.getStrokeWidth() : mProgPaint.getStrokeWidth()));int mRectL = getPaddingLeft() + (viewWide - mRectLength) / 2;int mRectT = getPaddingTop() + (viewHigh - mRectLength) / 2;mRectF = new RectF(mRectL, mRectT, mRectL + mRectLength, mRectT + mRectLength);centerX = getMeasuredWidth() / 2;centerY = getMeasuredHeight() / 2;//计算圆弧半径和圆心点circleRadius = Math.min(getMeasuredWidth(), getMeasuredHeight()) / 2;circleRadius-=8;// 设置进度圆环渐变色if (mColorArray != null && mColorArray.length > 1)mProgPaint.setShader(new LinearGradient(0, 0, 0, getMeasuredWidth(), mColorArray, null, Shader.TileMode.MIRROR));}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);canvas.drawArc(mRectF, 0, 360, false, mBackPaint);canvas.drawArc(mRectF, 270, 360 * mProgress / 100, false, mProgPaint);//绘制结束位置小圆形progressPaint.setStrokeWidth(10);progressPaint.setStyle(Paint.Style.FILL);float swipe = 360 * mProgress / 100;Log.d("=================", swipe + "        mProgress");float radians = (float) (((swipe - 90) / 2) / 180 * 2 * Math.PI);float endX;float endY;endX = centerX + circleRadius * (float) Math.cos(radians);endY = centerY + circleRadius * (float) Math.sin(radians);if (mProgress!=0) {canvas.drawCircle(endX, endY, 8, progressPaint);}}/*** 获取当前进度** @return 当前进度（0-100）*/public int getProgress() {return mProgress;}/*** 设置当前进度** @param progress 当前进度（0-100）*/public void setProgress(int progress) {this.mProgress = progress;invalidate();}/*** 设置当前进度，并展示进度动画。如果动画时间小于等于0，则不展示动画** @param progress 当前进度（0-100）* @param animTime 动画时间（毫秒）*/public void setProgress(int progress, long animTime) {if (animTime <= 0) setProgress(progress);else {ValueAnimator animator = ValueAnimator.ofInt(mProgress, progress);animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {@Overridepublic void onAnimationUpdate(ValueAnimator animation) {mProgress = (int) animation.getAnimatedValue();invalidate();}});animator.setInterpolator(new OvershootInterpolator());animator.setDuration(animTime);animator.start();}}/*** 设置背景圆环宽度** @param width 背景圆环宽度*/public void setBackWidth(int width) {mBackPaint.setStrokeWidth(width);invalidate();}/*** 设置背景圆环颜色** @param color 背景圆环颜色*/public void setBackColor(/*@ColorRes int color*/String color) {mBackPaint.setColor(Color.parseColor(color)); //画笔颜色invalidate();}/*** 设置进度圆环宽度** @param width 进度圆环宽度*/public void setProgWidth(int width) {mProgPaint.setStrokeWidth(width);invalidate();}/*** 设置进度圆环颜色** @param color 景圆环颜色*/public void setProgColor(/*@ColorRes int color*/String color) {mProgPaint.setColor(Color.parseColor(color)); //画笔颜色mProgPaint.setShader(null);invalidate();}/*** 设置进度圆环颜色(支持渐变色)** @param startColor 进度圆环开始颜色* @param firstColor 进度圆环结束颜色*/public void setProgColor(@ColorRes int startColor, @ColorRes int firstColor) {mColorArray = new int[]{ContextCompat.getColor(getContext(), startColor), ContextCompat.getColor(getContext(), firstColor)};mProgPaint.setShader(new LinearGradient(0, 0, 0, getMeasuredWidth(), mColorArray, null, Shader.TileMode.MIRROR));invalidate();}/*** 设置进度圆环颜色(支持渐变色)** @param colorArray 渐变色集合*/public void setProgColor(@ColorRes int[] colorArray) {if (colorArray == null || colorArray.length < 2) return;mColorArray = new int[colorArray.length];for (int index = 0; index < colorArray.length; index++)mColorArray[index] = ContextCompat.getColor(getContext(), colorArray[index]);mProgPaint.setShader(new LinearGradient(0, 0, 0, getMeasuredWidth(), mColorArray, null, Shader.TileMode.MIRROR));invalidate();}
}

attrs.xml

    <declare-styleable name="CircularProgressView"><attr name="backWidth" format="dimension" />    <!--背景圆环宽度--><attr name="progWidth" format="dimension" />    <!--进度圆环宽度--><attr name="progbgColor" format="color" />        <!--背景圆环颜色--><attr name="progColor" format="color" />        <!--进度圆环颜色--><attr name="progStartColor" format="color" />   <!--进度圆环开始颜色--><attr name="progFirstColor" format="color" />   <!--进度圆环结束颜色--><attr name="progress" format="integer" />       <!--圆环进度--></declare-styleable>

使用方法

<com.view.CircularProgressViewandroid:layout_width="170dp"android:layout_height="170dp"android:layout_centerInParent="true"android:layout_centerHorizontal="true"app:backWidth="5dp"app:progWidth="5dp"app:progbgColor="#4C5098"app:progress="50"android:layout_marginTop="500dp"/>