TRegistry.WriteDateTime Method

Stores a datetime value in a specifically named data value associated with the current key.

Pascal

procedure WriteDateTime(const Name: string; Value: TDateTime);

C++

__fastcall WriteDateTime(const AnsiString Name, TDateTime Value);

Description

Call WriteDateTime to store a datetime value in a data value associated with the current key.

Name is a string containing the name of the data value in which to store data. If Name already exists, its current value is overwritten by WriteDateTime. If Name does not exist, it is created.

Value is a datetime value to store in the registry.

If WriteDateTime fails, an exception is raised, and the value is not written to the registry.

If successful, WriteDateTime stores a TDateTime value. The integral part of a TDateTime value is the number of days that have passed since 12/30/1899. The fractional part of a TDateTime value is the time of day.

C++ Examples:

Copy Code

/*
This example shows how to use the TRegistry class in order to
find, insert and delete Keys and Items into the Windows Registry.
This example uses two buttons: InsertToRegBtn and DeleteFromRegBtn,
for inserting and deleting the values.
*/
void __fastcall TForm2::InsertToRegBtnClick(TObject *Sender)
{
    TRegistry* reg = new TRegistry(KEY_READ);
    reg->RootKey = HKEY_LOCAL_MACHINE;

    if(!reg->KeyExists("Software\\MyCompanyName\\MyApplication\\"))
    {
        MessageDlg("Key not found! Created now.",
                    mtInformation, TMsgDlgButtons() << mbOK, 0);
    }
    reg->Access = KEY_WRITE;
    bool openResult = reg->OpenKey("Software\\MyCompanyName\\MyApplication\\", true);

    if(!openResult)
    {
        MessageDlg("Unable to create key! Exiting.",
                    mtError, TMsgDlgButtons() << mbOK, 0);
        return;
    }
    //checking if the values exist and inserting when neccesary

    if(!reg->KeyExists("Creation\ Date"))
    {
        TDateTime today = TDateTime::CurrentDateTime();
        reg->WriteDateTime("Creation\ Date", today);
    }

    if(!reg->KeyExists("Licenced\ To"))
    {
        reg->WriteString("Licenced\ To", "MySurname\ MyFirstName");
    }

    if(!reg->KeyExists("App\ Location"))
    {
        reg->WriteExpandString("App\ Location",
                                "%PROGRAMFILES%\\MyCompanyName\\MyApplication\\");
    }

    if(!reg->KeyExists("Projects\ Location"))
    {
        reg->WriteExpandString("Projects\ Location",
                                "%USERPROFILE%\\MyApplication\\Projects\\");
    }

    reg->CloseKey();
}
//---------------------------------------------------------------------------
void __fastcall TForm2::DelFromRegBtnClick(TObject *Sender)
{
    //deleting the example registry entries
    TRegistry* reg = new TRegistry(KEY_WRITE);
    reg->RootKey = HKEY_LOCAL_MACHINE;

    reg->DeleteKey("Software\\MyCompanyName\\MyApplication");
    reg->DeleteKey("Software\\MyCompanyName");

    reg->CloseKey();
}
//---------------------------------------------------------------------------

Delphi Examples:

Copy Code

{
This example shows how to use the TRegistry class in order to
find, insert and delete Keys and Items into the Windows Registry.
This example uses two buttons: InsertToRegBtn and DeleteFromRegBtn,
on a form, for inserting and deleting the values.
}
procedure TForm3.InsertToRegBtnClick(Sender: TObject);
var
  reg        : TRegistry;
  openResult : Boolean;
  today      : TDateTime;
begin
  reg := TRegistry.Create(KEY_READ);
  reg.RootKey := HKEY_LOCAL_MACHINE;

  if (not reg.KeyExists('Software\\MyCompanyName\\MyApplication\\')) then
    begin
      MessageDlg('Key not found! Created now.',
                            mtInformation, mbOKCancel, 0);
    end;
  reg.Access := KEY_WRITE;
  openResult := reg.OpenKey('Software\\MyCompanyName\\MyApplication\\',True);

  if not openResult = True then
    begin
      MessageDlg('Unable to create key! Exiting.',
                  mtError, mbOKCancel, 0);
      Exit();
    end;

  {checking if the values exist and inserting when neccesary}

  if not reg.KeyExists('Creation\ Date') then
    begin
      today := Now;
        reg.WriteDateTime('Creation\ Date', today);
    end;

  if not reg.KeyExists('Licenced\ To') then
    begin
        reg.WriteString('Licenced\ To', 'MySurname\ MyFirstName');
    end;

  if not reg.KeyExists('App\ Location') then
    begin
        reg.WriteExpandString('App\ Location',
                            '%PROGRAMFILES%\\MyCompanyName\\MyApplication\\');
    end;

  if not reg.KeyExists('Projects\ Location') then
    begin
        reg.WriteExpandString('Projects\ Location',
                            '%USERPROFILE%\\MyApplication\\Projects\\');
    end;

  reg.CloseKey();

end;

procedure TForm3.DeleteFromRegBtnClick(Sender: TObject);
var
  reg : TRegistry;
begin
  reg := TRegistry.Create(KEY_WRITE);
  reg.RootKey := HKEY_LOCAL_MACHINE;

  reg.DeleteKey('Software\\MyCompanyName\\MyApplication');
  reg.DeleteKey('Software\\MyCompanyName');

  reg.CloseKey();
end;