public class DoughnutProgress extends View {

  }

private static final int DEFAULT_MIN_WIDTH = 400; //View默认最小宽度
  private static final int RED = 230, GREEN = 85, BLUE = 35; //基础颜色，这里是橙红色
  private static final int MIN_ALPHA = 30; //最小不透明度
  private static final int MAX_ALPHA = 255; //最大不透明度
  private static final float doughnutRaduisPercent = 0.65f; //圆环外圆半径占View最大半径的百分比
  private static final float doughnutWidthPercent = 0.12f; //圆环宽度占View最大半径的百分比
  private static final float MIDDLE_WAVE_RADUIS_PERCENT = 0.9f; //第二个圆出现时，第一个圆的半径百分比
  private static final float WAVE_WIDTH = 5f; //波纹圆环宽度

  //圆环颜色
  private static int[] doughnutColors = new int[]{
      Color.argb(MAX_ALPHA, RED, GREEN, BLUE),
      Color.argb(MIN_ALPHA, RED, GREEN, BLUE),
      Color.argb(MIN_ALPHA, RED, GREEN, BLUE)};

  private Paint paint = new Paint(); //画笔
  private float width; //自定义view的宽度
  private float height; //自定义view的高度
  private float currentAngle = 0f; //当前旋转角度
  private float raduis; //自定义view的最大半径
  private float firstWaveRaduis;
  private float secondWaveRaduis;

  //
  private void resetParams() {
    width = getWidth();
    height = getHeight();
    raduis = Math.min(width, height)/2;
  }

  private void initPaint() {
    paint.reset();
    paint.setAntiAlias(true);
  }

  /**
   * 当布局为wrap_content时设置默认长宽
   *
   * @param widthMeasureSpec
   * @param heightMeasureSpec
   */
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(measure(widthMeasureSpec), measure(heightMeasureSpec));
  }

  private int measure(int origin) {
    int result = DEFAULT_MIN_WIDTH;
    int specMode = MeasureSpec.getMode(origin);
    int specSize = MeasureSpec.getSize(origin);
    if (specMode == MeasureSpec.EXACTLY) {
      result = specSize;
    } else {
      if (specMode == MeasureSpec.AT_MOST) {
        result = Math.min(result, specSize);
      }
    }
    return result;
  }

  resetParams();

  //将画布中心设为原点(0,0), 方便后面计算坐标
  canvas.translate(width / 2, height / 2);

  float doughnutWidth = raduis * doughnutWidthPercent;//圆环宽度
   //圆环外接矩形
   RectF rectF = new RectF(
   -raduis * doughnutRaduisPercent, 
   -raduis * doughnutRaduisPercent, 
   raduis * doughnutRaduisPercent, 
   raduis * doughnutRaduisPercent);
   initPaint();
   paint.setStrokeWidth(doughnutWidth);
   paint.setStyle(Paint.Style.STROKE);
   paint.setShader(new SweepGradient(0, 0, doughnutColors, null));
   canvas.drawArc(rectF, 0, 360, false, paint);

  //画旋转头部圆
   initPaint();
   paint.setStyle(Paint.Style.FILL);
   paint.setColor(Color.argb(MAX_ALPHA, RED, GREEN, BLUE));
   canvas.drawCircle(raduis * doughnutRaduisPercent, 0, doughnutWidth / 2, paint);

  //转起来
  canvas.rotate(-currentAngle, 0, 0);
  if (currentAngle >= 360f){
    currentAngle = currentAngle - 360f;
  } else{
    currentAngle = currentAngle + 2f;
  }

private Thread thread = new Thread(){
  @Override
  public void run() {
    while(true){
      try {
        Thread.sleep(10);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      postInvalidate();
    }
  }
};

  //实现类似水波涟漪效果
  initPaint();
  paint.setStyle(Paint.Style.STROKE);
  paint.setStrokeWidth(5);
  secondWaveRaduis = calculateWaveRaduis(secondWaveRaduis);
  firstWaveRaduis = calculateWaveRaduis(secondWaveRaduis + raduis*(MIDDLE_WAVE_RADUIS_PERCENT - doughnutRaduisPercent) - raduis*doughnutWidthPercent/2);
  paint.setColor(Color.argb(calculateWaveAlpha(secondWaveRaduis), RED, GREEN, BLUE));
  canvas.drawCircle(0, 0, secondWaveRaduis, paint); //画第二个圆（初始半径较小的）

  initPaint();
  paint.setStyle(Paint.Style.STROKE);
  paint.setStrokeWidth(5);
  paint.setColor(Color.argb(calculateWaveAlpha(firstWaveRaduis), RED, GREEN, BLUE));
  canvas.drawCircle(0, 0, firstWaveRaduis, paint); //画第一个圆（初始半径较大的）


  /**
   * 计算波纹圆的半径
   * @param waveRaduis
   * @return
   */
  private float calculateWaveRaduis(float waveRaduis){
    if(waveRaduis < raduis*doughnutRaduisPercent + raduis*doughnutWidthPercent/2){
      waveRaduis = raduis*doughnutRaduisPercent + raduis*doughnutWidthPercent/2;
    }
    if(waveRaduis > raduis*MIDDLE_WAVE_RADUIS_PERCENT + raduis*(MIDDLE_WAVE_RADUIS_PERCENT - doughnutRaduisPercent) - raduis*doughnutWidthPercent/2){
      waveRaduis = waveRaduis - (raduis*MIDDLE_WAVE_RADUIS_PERCENT + raduis*(MIDDLE_WAVE_RADUIS_PERCENT - doughnutRaduisPercent) - raduis*doughnutWidthPercent/2) + raduis*doughnutWidthPercent/2 + raduis*doughnutRaduisPercent;
    }
      waveRaduis += 0.6f;
    return waveRaduis;
  }

  /**
   * 根据波纹圆的半径计算不透明度
   * @param waveRaduis
   * @return
   */
  private int calculateWaveAlpha(float waveRaduis){
    float percent = (waveRaduis-raduis*doughnutRaduisPercent-raduis*doughnutWidthPercent/2)/(raduis-raduis*doughnutRaduisPercent-raduis*doughnutWidthPercent/2);
    if(percent >= 1f){
      return 0;
    }else{
      return (int) (MIN_ALPHA*(1f-percent));
    }
  }