添加文字 about datepicker

[ycuwq]

添加文字使用setDataFormat处理 类似 #9
这种情况可以使用自定义format 例如:

DatePicker datePicker = findViewById(R.id.datePicker);
datePicker.getDayPicker().setVisibility(View.GONE);
datePicker.setMaxDate(System.currentTimeMillis());
Calendar calendar = Calendar.getInstance();
int currentYear = calendar.get(Calendar.YEAR);
int currentMonth = calendar.get(Calendar.MONTH) + 1;
Format monthFormat = new Format() {
    @NonNull
    @Override
    public StringBuffer format(Object obj,
                               StringBuffer toAppendTo,
                               FieldPosition pos) {
        int month;
        if (obj instanceof Number) {
            month = ((Number) obj).intValue();
        } else {
            month = Integer.parseInt(obj.toString());
        }
        return datePicker.getYear() == currentYear && currentMonth == month ? new StringBuffer("至今") : new StringBuffer(String.valueOf(month));
    }

    @Override
    public Object parseObject(String source, ParsePosition pos) {
        return null;
    }

};
datePicker.getMonthPicker().setDataFormat(monthFormat);