public MyCalendar(Context context) {
    super(context);
  }

  public MyCalendar(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);

  }

  /**
   * 暴露接口，设置日期
   *
   * @param customDate
   */
  public void setDate(CustomDate customDate) {
    Log.d(TAG, customDate.toString());
    this.date = customDate;
    firstDayOfWeek = date.getFirstDayOfWeek();
    Log.d(TAG, (date.getMonth() + 1) + "月1号是星期" + firstDayOfWeek);
    lastDayOfWeek = date.getLastDayOfWeek();
    lineCount = calculateLineNum() + 1;
    lastMonthTotalDays = date.getLastMonthDays();
  }

  /**
   * 暴露接口，设置是否周末高亮
   *
   * @param b
   */
  public void setWeekendHighLight(boolean b) {
    this.weekendHighlight = b;
  }

  public void setSpecialDay(int[] ints) {
    this.specialDays = ints;
  }

  /**
   * 暴露接口，设置是否可以点击前一个月和后一个月的日期
   *
   * @param b
   */
  public void setCanClickNextOrPreMonth(boolean b) {
    this.canClickNextOrPreMonth = b;
  }

 /**
   * 获得应该设置为多少行
   *
   * @return
   */
  private int calculateLineNum() {
    monthDaySum = date.getTotalDayOfMonth();
    return (firstDayOfWeek - 1 + monthDaySum) / 7;
  }

 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    this.viewWidth = w;
    this.viewHeight = h;
    Log.d(TAG, "onSizeChanged" + w + h);
    cutGrid();
    init();
    setCellDay();
  }

 /**
   * 切分为每天
   */
  private void cutGrid() {
    cellWidth = (float) viewWidth / ROW_COUNT;
    cellHeight = (float) viewHeight / lineCount;
    this.radius = Math.min(cellWidth / 2, cellHeight / 2);
    for (int i = 0; i < lineCount; i++) {
      for (int j = 0; j < ROW_COUNT; j++) {
        points.add(new PointF(cellWidth * j + cellWidth / 2, cellHeight * i + cellHeight / 2));
      }
    }
  }

private void init() {
    circlePaint = new Paint();
    circlePaint.setStyle(Paint.Style.STROKE);
    circlePaint.setAntiAlias(true);
    circlePaint.setColor(Color.BLUE);
    textPaint = new Paint();
    textPaint.setAntiAlias(true);
    textPaint.setColor(Color.BLACK);
    textPaint.setTextSize(radius / 2);
    selectPaint = new Paint();
    selectPaint.setColor(Color.YELLOW);
    selectPaint.setAlpha(10);
    selectPaint.setAntiAlias(true);
    selectPaint.setStyle(Paint.Style.FILL);
    selectTextPaint = new Paint();
    selectTextPaint.setColor(Color.WHITE);
    selectTextPaint.setAntiAlias(true);
    selectTextPaint.setTextSize(radius / 2);
    selectTextPaint.setStyle(Paint.Style.FILL);
  }

 /**
   * 设置总共显示多少天，每天的状态
   */
  private void setCellDay() {
    cellDays = new CellDay[lineCount * ROW_COUNT];
    for (int i = 0, length = cellDays.length; i < length; i++) {
      cellDays[i] = new CellDay();
      cellDays[i].setPointX(points.get(i).x);
      cellDays[i].setPointY(points.get(i).y);
      if (firstDayOfWeek > 1 && i < firstDayOfWeek - 1) {
        cellDays[i].setDayState(DayState.LASTMONTH);
        cellDays[i].setDate(String.valueOf(lastMonthTotalDays - firstDayOfWeek + i + 2));
        cellDays[i].setCustomDate(new CustomDate(
            date.getYear(), date.getMonth() - 1, lastMonthTotalDays - firstDayOfWeek + i + 2));
      }
      if (i >= firstDayOfWeek - 1 && i < monthDaySum + firstDayOfWeek - 1) {

        cellDays[i].setDayState(CURRENTMONTH);
        cellDays[i].setDate(String.valueOf(i + 2 - firstDayOfWeek));
        cellDays[i].setCustomDate(new CustomDate(
            date.getYear(), date.getMonth(), i - firstDayOfWeek + 2));
        //设置周末高亮
        if (weekendHighlight) {
          if (i % 7 == 0 || i % 7 == 6) {
            cellDays[i].setDayState(WEEKEND);
          }
        }
      }
      if (i >= monthDaySum + firstDayOfWeek - 1) {
        cellDays[i].setDayState(NEXTMONTH);
        cellDays[i].setDate(String.valueOf(i - monthDaySum - firstDayOfWeek + 2));
        cellDays[i].setCustomDate(new CustomDate(
            date.getYear(), date.getMonth() + 1, i - monthDaySum - firstDayOfWeek + 2));
      }
      for (int j = 0, s = specialDays.length; j < s; j++) {
        if (specialDays[j] + firstDayOfWeek - 2 == i) {
          cellDays[i].setDayState(SPECIALDAY);
        }
      }
    }
  }

    private String date;
    private DayState dayState;
    private CustomDate customDate;
    private float pointX;
    private float pointY;
    private boolean isSelected;

public class CustomDate {
  private Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT+8"));
  private int year;
  private int month;
  private int day;
  private int dayOfWeek;

  public CustomDate() {
  }

  /**
   * 获取当前的日期
   * @return
   */
  public CustomDate getCurrentDate() {
    this.year = calendar.get(Calendar.YEAR);
    this.month = calendar.get(Calendar.MONTH);
    this.day = calendar.get(Calendar.DAY_OF_MONTH);
    this.dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
    return new CustomDate(year, month, day);
  }

  public CustomDate(int year, int month, int day) {
    this.year = year;
    this.month = month;
    this.day = day;
    calendar.set(year, month, day);
    dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
  }

  /**
   * 获取上个月的天数
   * @return
   */
  public int getLastMonthDays() {
    return this.getDaysOfMonth(this.year, this.month - 1);
  }

  /**
   * 获取第一天是星期几
   *
   * @return
   */
  public int getFirstDayOfWeek() {
    calendar.set(this.year, this.month, 1);
    return calendar.get(Calendar.DAY_OF_WEEK);
  }

  /**
   * 获取最后一天是星期几
   *
   * @return
   */
  public int getLastDayOfWeek() {
    calendar.set(this.year, this.month, getTotalDayOfMonth());
    return calendar.get(Calendar.DAY_OF_WEEK);
  }

  /**
   * 获取这个月总共的天数
   * @return
   */
  public int getTotalDayOfMonth() {
    return this.getDaysOfMonth(year, month);
  }

  public int getTotalWeekOfMonth() {
    return calendar.getMaximum(Calendar.WEEK_OF_MONTH);
  }

  public int getYear() {
    return year;
  }

  public void setYear(int year) {
    this.year = year;
  }

  public int getMonth() {
    return month;
  }

  public void setMonth(int month) {
    this.month = month;
  }

  public int getDay() {
    return day;
  }

  public void setDay(int day) {
    this.day = day;
  }

  public int getDayOfWeek() {
    return dayOfWeek;
  }

  public void setDayOfWeek(int dayOfWeek) {
    this.dayOfWeek = dayOfWeek;
  }

  @Override
  public String toString() {
    return "CustomDate{" +
        "year=" + year +
        ", month=" + (getMonth() + 1) +
        ", day=" + day +
        ", dayOfWeek=" + dayOfWeek +
        '}';
  }

  /**
   * 获取年中每月的天数
   * @param year
   * @param month
   * @return
   */
  private int getDaysOfMonth(int year, int month) {
    if (month > 11) {
      month = 0;
      year += 1;
    } else if (month < 0) {
      month = 11;
      year -= 1;
    }

    int[] arr = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int daysOfMonth = 0;
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
      arr[1] = 29;
    }
    daysOfMonth = arr[month];
    return daysOfMonth;
  }
}

int getLastMonthDays()

getFirstDayOfWeek()

int getTotalDayOfMonth()