//提供对外暴露的属性,如有不够自己扩展
  <declare-styleable name="DescProgressView">
    <attr name="dpv_text_normal_color" format="color" />
    <attr name="dpv_text_seleced_color" format="color" />
    <attr name="dpv_text_size" format="dimension" />
    <attr name="dev_progress_bg_color" format="color" />
    <attr name="dev_progress_small_circle_color" format="color" />
    <attr name="dev_progress_big_circle_color" format="color" />
  </declare-styleable>

private void initAttrs(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
    TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.DescProgressView, defStyleAttr, R.style.Def_DescProgressViewStyle);
    int indexCount = typedArray.getIndexCount();
    for (int i = 0; i < indexCount; i++) {
      int attr = typedArray.getIndex(i);
      switch (attr) {
        case R.styleable.DescProgressView_dpv_text_normal_color:
          textNormalColor = typedArray.getColor(attr, Color.BLACK);
          break;
        case R.styleable.DescProgressView_dpv_text_seleced_color:
          textSelectedColor = typedArray.getColor(attr, Color.BLACK);
          break;
        case R.styleable.DescProgressView_dpv_text_size:
          dpvTextSize = typedArray.getDimensionPixelSize(attr, 0);
          break;
        case R.styleable.DescProgressView_dev_progress_bg_color:
          dpvProgressBgColor = typedArray.getColor(attr, Color.BLACK);
          break;
        case R.styleable.DescProgressView_dev_progress_small_circle_color:
          dpvSmallCicleColor = typedArray.getColor(attr, Color.BLACK);
          break;
        case R.styleable.DescProgressView_dev_progress_big_circle_color:
          dpvBigCircleColor = typedArray.getColor(attr, Color.BLACK);
          break;
      }
    }
    typedArray.recycle();
  }

//这里大家可以根据自己的习惯来,我习惯用view的尺寸当做参照,来约束界面的view,各有利弊,也可以暴露出属性设置具体的dp值,根据比例的话,调整好比例后,所有的绘制内容会统一约束
  private static final float SCALE_OF_PROGRESS_HEIGHT = 70.F / 120;
  private static final float SCALE_OF_TOP_AND_BOTTOM_PADDING = 10.F / 120;
  private static final float SCALE_OF_LEFT_AND_RIGHT_PADDING = 20.F / 120;
  private static final float SCALE_OF_TEXT_DESC_CONTAINER = 50.F / 120;
  private static final float SCALE_OF_BIG_CIRCLE_HEIGHT = 22.F / 120;
  private static final float SCALE_OF_SMALL_CIRCLE_HEIGHT = 16.F / 120;
  private static final float SCALE_OF_LINE_HEIGHT = 4.F / 120;
  private static final float DEF_VIEW_HEIGHT = 120.F;

 /**
   * 获取文字在画布中的位置
   */
  private void getDescTextRegonPoint() {
    for (int i = 0; i < descs.size(); i++) {
      Point textRegonPoint = new Point();
      int sumX = 0;
      //非常重要:计算各个文字在view中的具体坐标,体会下这个二级for循环,子循环是确定每个描述文本的位置
      for (int j = 0; j < i; j++) {
        Point tempSum = allDescTextPoints.get(j);
        sumX += tempSum.x;
      }
      sumX += i * getTextDescSpace();
      textRegonPoint.x = sumX + leftAndRightPadding;
      textRegonPoint.y = dpViewHeight - topAndBottomPadding - textDescContainerHeight / 2;
      textPoints4Draw.add(textRegonPoint);
    }
  }

 /**
   * 获取文字的间距
   *
   * @return 获取文字的间距
   */
  private float getTextDescSpace() {
    float allDescWith = 0;
    for (Point tempDesc : allDescTextPoints) {
      allDescWith += tempDesc.x;
    }
    int textContainerW = (int) (dpViewWidth - leftAndRightPadding * 2 - allDescWith);
    if (descs != null && descs.size() > 1) {
      int spaceCount = descs.size() - 1;
      return textContainerW * 1.F / spaceCount;
    }
    return 0;
  }

 @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  // 确定各个比例的大小
    super.onSizeChanged(w, h, oldw, oldh);
    dpViewHeight = h;
    dpViewWidth = w;
    progressContainerHeight = (int) (SCALE_OF_PROGRESS_HEIGHT * dpViewHeight);
    topAndBottomPadding = (int) (SCALE_OF_TOP_AND_BOTTOM_PADDING * dpViewHeight);
    leftAndRightPadding = (int) (SCALE_OF_LEFT_AND_RIGHT_PADDING * dpViewHeight);
    textDescContainerHeight = (int) (SCALE_OF_TEXT_DESC_CONTAINER * dpViewHeight);
    smallCircleRadio = (int) (SCALE_OF_SMALL_CIRCLE_HEIGHT * dpViewHeight / 2);
    bigCircleRadio = (int) (SCALE_OF_BIG_CIRCLE_HEIGHT * dpViewHeight / 2);
    lineHeight = (int) (SCALE_OF_LINE_HEIGHT * dpViewHeight);

    // 获取各个部分所需要的约束坐标
    getDescTextWidthAndHeight();
    getDescTextRegonPoint();
    getBgLineRectF();
    getBgCirclePoints();
    getSelectedRectF();
    getColorFullRectF();
    getGrayRectF();
  }

@Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  drawDescText(canvas);
  drawBgLine(canvas);
  drawSelectedLine(canvas);
  drawGrayRectF(canvas);
  drawSelectedCircles(canvas);
 }
//绘制部分的代码就是canvas 的API的使用,没有什么技术含量.
//最后暴露给外面设置数据的接口

public void setProgressDescs(List<String> descs, int currentSelectPosition) {
  this.currentSelectPosition = currentSelectPosition;
  if (descs != null && descs.size() > 1) {
   this.descs.clear();
   this.descs.addAll(descs);
   this.allDescTextPoints.clear();
   invalidate();
  }
 }