DTValid (C++)

Description

 This example demonstrates the use of the decoding and recoding routines
 used for TDateTime variables.

 TDateTime DateTime;
 Word month, year, week, nthday, dayy, dayw, weeky;

---

Code

__fastcall TMainForm::TMainForm(TComponent* Owner)
        : TForm(Owner)
{
  /* Initialize the variable with the current date */
  DateTime = Date();
  edDate->Text = DateToStr(DateTime);
}
//---------------------------------------------------------------------------
void __fastcall TMainForm::btDecodeClick(TObject *Sender)
{
  /* Decode the date */
  if (rgDecode->ItemIndex == 0)
        {
        DecodeDateDay(DateTime, year, dayy);
        edDayYear->Text = IntToStr(dayy);
        edYear->Text = IntToStr(year);
        };
  if (rgDecode->ItemIndex == 1)
        {
        DecodeDateWeek(DateTime,year,weeky,dayw);
        edYear->Text = IntToStr(year);
        edWeekYear->Text = IntToStr(weeky);
        edDayWeek->Text = IntToStr(dayw);
        };
  if (rgDecode->ItemIndex == 2)
        {
        DecodeDateMonthWeek(DateTime,year,month,week,dayw);
        edYear->Text = IntToStr(year);
        edMonth->Text = IntToStr(month);
        edWeek->Text = IntToStr(week);
        edDayWeek->Text = IntToStr(dayw);
        };
  if (rgDecode->ItemIndex == 3)
        {
        DecodeDayOfWeekInMonth(DateTime,year,month,nthday,dayw);
        edYear->Text = IntToStr(year);
        edMonth->Text = IntToStr(month);
        edDayWM->Text = IntToStr(nthday);
        edDayWeek->Text = IntToStr(dayw);
        };
}
//---------------------------------------------------------------------------
 
void __fastcall TMainForm::btEncodeClick(TObject *Sender)
{
  /* Encode the date */
  if (rgEncode->ItemIndex == 0)
        {
        dayy = StrToInt(edDayYear->Text);
        year = StrToInt(edYear->Text);
        if (IsValidDateDay(year,dayy)) {
                DateTime = EncodeDateDay(year,dayy);
        edDate->Text = DateTimeToStr(DateTime);
      } else
      ShowMessage("Not a valid date");
        };
  if (rgEncode->ItemIndex == 1)
    {
    dayw = StrToInt(edDayWeek->Text);
    year = StrToInt(edYear->Text);
    weeky = StrToInt(edWeekYear->Text);
    if (IsValidDateWeek(year,weeky,dayw)) {
        DateTime = EncodeDateWeek(year,weeky,dayw);
        edDate->Text = DateTimeToStr(DateTime);
      } else
      ShowMessage("Not a valid date");
    };
  if (rgEncode->ItemIndex == 2)
    {
    dayw = StrToInt(edDayWeek->Text);
    year = StrToInt(edYear->Text);
    month = StrToInt(edMonth->Text);
    week = StrToInt(edWeek->Text);
        if (IsValidDateMonthWeek(year, month, week, dayw)) {
          DateTime = EncodeDateMonthWeek(year,month,week,dayw);
      edDate->Text = DateTimeToStr(DateTime);
    } else
          ShowMessage("Not a valid date");
    };
  if (rgEncode->ItemIndex == 3)
        {
        dayw = StrToInt(edDayWeek->Text);
    year = StrToInt(edYear->Text);
    month = StrToInt(edMonth->Text);
    nthday = StrToInt(edDayWM->Text);
    DateTime = EncodeDayOfWeekInMonth(year,month,nthday,dayw);
        edDate->Text = DateTimeToStr(DateTime);
        };
}

Uses

• System.DateUtils.DecodeDateDay ( fr | de | ja )
• System.DateUtils.DecodeDateMonthWeek ( fr | de | ja )
• System.DateUtils.DecodeDateWeek ( fr | de | ja )
• System.DateUtils.DecodeDayOfWeekInMonth ( fr | de | ja )
• System.DateUtils.EncodeDateDay ( fr | de | ja )
• System.DateUtils.EncodeDateMonthWeek ( fr | de | ja )
• System.DateUtils.EncodeDateWeek ( fr | de | ja )
• System.DateUtils.EncodeDayOfWeekInMonth ( fr | de | ja )
• System.DateUtils.IsValidDateDay ( fr | de | ja )
• System.DateUtils.IsValidDateMonthWeek ( fr | de | ja )
• System.DateUtils.IsValidDateWeek ( fr | de | ja )