如何仅显示当前月份并预览可在日期选择对话框中选择的月份日期？

Question

仅在日期选择器对话框中显示当前和上个月。

  datePickerDialog = new DatePickerDialog(DateConvertActivity.this, new DatePickerDialog.OnDateSetListener() {
  @Override
   public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
                    String s = "" + dayOfMonth + "-" + (month + 1) + "-" + year;
                    edtDate.setText(s);
            }
      }, mDay, mMonth, mYear);
            datePickerDialog.getDatePicker().updateDate(mYear, mMonth, mDay);

Answer 1

在时间戳中选择日期请参见下面的代码

Long tsLong = System.currentTimeMillis()

然后将tsLong转换为任何特定格式并提取所需的格式。

供参考：Android Timestamp

Answer 2

尝试此解决方案。从上个月的第一天到今天。

在Kotlin中：

private fun setupUi() {
    // Get calendar instance
    val calendar = Calendar.getInstance()
    // Get current time
    val currentYear = calendar.get(Calendar.YEAR)
    val currentMonth = calendar.get(Calendar.MONTH)
    val currentDay = calendar.get(Calendar.DAY_OF_MONTH)
    // Create listener
    val listener = DatePickerDialog.OnDateSetListener { view, year, month, day ->
        // Show Toast after selection
        Toast.makeText(this, "Selected: $day.$month.$year", Toast.LENGTH_SHORT).show()
    }
    // Max = current
    val maxTime = calendar.timeInMillis
    // Move day as first day of the month
    calendar.set(Calendar.DAY_OF_MONTH, 1)
    // Move "month" for previous one
    calendar.add(Calendar.MONTH, -1)
    // Min = time after changes
    val minTime = calendar.timeInMillis
    // Create dialog
    val datePickerDialog = DatePickerDialog(
        this,
        listener,
        currentYear,
        currentMonth,
        currentDay
    ).apply {
        // Set dates
        datePicker.maxDate = maxTime
        datePicker.minDate = minTime
    }
    // Show dialog
    datePickerDialog.show()
}

和in Java：

private void setupUi() {
    // Get calendar instance
    Calendar calendar = Calendar.getInstance();
    // Get current time
    int currentYear = calendar.get(Calendar.YEAR);
    int currentMonth = calendar.get(Calendar.MONTH);
    int currentDay = calendar.get(Calendar.DAY_OF_MONTH);
    // Create listener
    DatePickerDialog.OnDateSetListener listener = new DatePickerDialog.OnDateSetListener() {
        @Override
        public void onDateSet(DatePicker view, int year, int month, int day) {
            // Show Toast after selection
            Toast.makeText(MainActivity.this, String.format("Selected: %s.%s.%s", day, month, year), Toast.LENGTH_SHORT).show();
        }
    };
    // Max = current
    long maxTime = calendar.getTimeInMillis();
    // Move day as first day of the month
    calendar.set(Calendar.DAY_OF_MONTH, 1);
    // Move "month" for previous one
    calendar.add(Calendar.MONTH, -1);
    // Min = time after changes
    long minTime = calendar.getTimeInMillis();
    // Create dialog
    DatePickerDialog datePickerDialog = new DatePickerDialog(
            this,
            listener,
            currentYear,
            currentMonth,
            currentDay
    );
    // Set dates
    datePickerDialog.getDatePicker().setMaxDate(maxTime);
    datePickerDialog.getDatePicker().setMinDate(minTime);
    // Show dialog
    datePickerDialog.show();
}

如果您需要整个当月（从第一天到最后一天），则可以用此 kotlin代码替换PAR：

// Move day as first day of the month
calendar.set(Calendar.DAY_OF_MONTH, 1)
// Move "month" for previous one
calendar.add(Calendar.MONTH, -1)
// Min = time after changes
val minTime = calendar.timeInMillis

// Move day as first day of the month
calendar.set(Calendar.DAY_OF_MONTH, 1)
// Move to next month
calendar.add(Calendar.MONTH, +2)
// Go back one day (so last day of current month)
calendar.add(Calendar.DAY_OF_MONTH, -1)
// Max = current
val maxTime = calendar.timeInMillis

和in Java：

// Move day as first day of the month
calendar.set(Calendar.DAY_OF_MONTH, 1);
// Move "month" for previous one
calendar.add(Calendar.MONTH, -1);
// Min = time after changes
long minTime = calendar.getTimeInMillis();
// Move day as first day of the month
calendar.set(Calendar.DAY_OF_MONTH, 1);
// Move to next month
calendar.add(Calendar.MONTH, +2);
// Go back one day (so last day of current month)
calendar.add(Calendar.DAY_OF_MONTH, -1);
// Max = current
long maxTime = calendar.getTimeInMillis();

Answer 3

datePickerDialog.getDatePicker().setMinDate(System.currentTimeMillis() - 1000);