Java 如何使用DateTimePicker获取一周中某一天的名称

我想在DateTimePicker中选择日期后获得一天的名称，如（星期一、星期二等）

DatePickerDialog  datePickerDialog = new DatePickerDialog (RegisterStudent.this, new DatePickerDialog.OnDateSetListener() {
        @Override
        public void onDateSet(DatePicker datePicker, int i, int i1, int i2) {

            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");

            //this is where I getting the wrong results it gives me thursday only even if i changethe day
            String dayName=simpleDateFormat.format(i2);


            _dob.setText(String.valueOf(dayName+","+ getMonthForInt(i1) +" " +datePicker.getDayOfMonth()+ ", " + i));

        }
    },mYear,mMonth,mDay);

通过这个我可以知道月份的名称

  private String getMonthForInt(int num) {
    String month = "wrong";
    DateFormatSymbols dfs = new DateFormatSymbols();
    String[] months = dfs.getMonths();
    if (num >= 0 && num <= 11 ) {
        month = months[num];
    }
    return month;

}

我得到的结果

 Thursday, Januar 12, 2019
 Thursday, October 13, 2020//always thursday

---

我认为没有理由将

COMMPORT

作为

ref

只需编辑类，问题就解决了

public SMSCOMMS(string COMMPORT)

---

在类的构造函数中使用ref关键字，因此在实例化类时，需要在参数中包含ref关键字

像这样：

 try
        {
            string test = "COM1";
            SMSCOMMS SMSEngine = new SMSCOMMS(ref test);
            SMSEngine.Open();
            SMSEngine.SendSMS("09xxxxxxxxx", "THIS IS YOUR MESSAGE");
            SMSEngine.Close();

        }
        catch (Exception ee) {
            MessageBox.Show(ee.Message);
        }

---

创建一个var并将其作为ref传递。或者将ref从中取出。编译器将错误指向哪一行？嗨，请重新打开我的问题，以便回答它。我今天编辑

 try
        {
            string test = "COM1";
            SMSCOMMS SMSEngine = new SMSCOMMS(ref test);
            SMSEngine.Open();
            SMSEngine.SendSMS("09xxxxxxxxx", "THIS IS YOUR MESSAGE");
            SMSEngine.Close();

        }
        catch (Exception ee) {
            MessageBox.Show(ee.Message);
        }