java - 从 DatePicker 和 TimePicker 获取时间戳

Question

我有一个应用程序，用户在其中使用 DatePicker 和 TimePicker 设置日期和时间。我正在尝试将信息保存为时间戳。我目前正在根据用户选择的日期获取时间戳(请参阅下面的代码):

                Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
                final Calendar c = cal.getInstance();
                int mYear = c.get(Calendar.YEAR); // current year
                int mMonth = c.get(Calendar.MONTH); // current month
                int mDay = c.get(Calendar.DAY_OF_MONTH); // current day
                // date picker dialog
                DatePickerDialog datePickerDialog = new DatePickerDialog(AddEventActivity.this,
                        new DatePickerDialog.OnDateSetListener() {

                            @Override
                            public void onDateSet(DatePicker view, int year,
                                                  int monthOfYear, int dayOfMonth) {
                                // set day of month , month and year value in the edit text
                                txtDate.setText(dayOfMonth + "/"
                                        + (monthOfYear + 1) + "/" + year);
                                c.set(year, monthOfYear, dayOfMonth);
                                timestamp = c.getTimeInMillis();
                            }

这工作正常，但由于我没有给出时间，它将时间设置为我创建项目的时间。例如，假设我在 27/4/2019 19:00 设置了一个事件，并在 13:30 保存，则记录的时间戳为 27/4/2019 13:30。

我的 TimePicker 的代码如下:

        txtTime.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Calendar mcurrentTime = Calendar.getInstance();
                int hour = mcurrentTime.get(Calendar.HOUR_OF_DAY);
                int minute = mcurrentTime.get(Calendar.MINUTE);

                TimePickerDialog mTimePicker;
                mTimePicker = new TimePickerDialog(AddEventActivity.this, new TimePickerDialog.OnTimeSetListener() {
                    @Override
                    public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) {
                        //adding extra 0 to the front of 1 digit hours and minutes so format is consistent.
                        String hourFormat = String.format("%02d", selectedHour);
                        String minFormat = String.format("%02d", selectedMinute);
                        txtTime.setText(hourFormat + ":" + minFormat);
                    }
                }, hour, minute, true);
                mTimePicker.show();
            }
        });

有没有办法结合所选的日期和时间来创建准确的时间戳？

Answer 1

有一个类级别的日历实例，让我们按照之前的方式实例化它:

Calendar combinedCal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));

因此，当您选择日期时，请按如下方式设置值:

combinedCal.set(year, monthOfYear, dayOfMonth);

当您选择时间时，只需将选定的小时和分钟设置为同一实例即可:

combinedCal.set(Calendar.HOUR_OF_DAY, selectedHour);
combinedCal.set(Calendar.MINUTE, selectedMinute);