//提供對外暴露的屬性,如有不夠自己擴展  <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();  }

//這里大家可以根據自己的習慣來,我習慣用view的尺寸當做參照,來約束界面的view,各有利弊,也可以暴露出屬性設置具體的dp值,根據比例的話,調整好比例后,所有的繪制內容會統一約束  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;

 /**   * 獲取文字在畫布中的位置   */  private void getDescTextRegonPoint() {    for (int i = 0; i < descs.size(); i++) {      Point textRegonPoint = new Point();      int sumX = 0;      //非常重要:計算各個文字在view中的具體坐標,體會下這個二級for循環,子循環是確定每個描述文本的位置      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);    }  }

 /**   * 獲取文字的間距   *   * @return 獲取文字的間距   */  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) {  // 確定各個比例的大小    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);    // 獲取各個部分所需要的約束坐標    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); }//繪制部分的代碼就是canvas 的API的使用,沒有什么技術含量.//最后暴露給外面設置數據的接口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();  } }