TRegistryIniFile.ReadString Method

Retrieves a string value from an INI file.

Pascal

function ReadString(const Section: string; const Ident: string; const Default: string): string; override;

C++

virtual __fastcall AnsiString ReadString(const AnsiString Section, const AnsiString Ident, const AnsiString Default);

Description

Call ReadString to read a string value from an INI file. Section identifies the section in the file that contains the desired key. Ident is the name of the key from which to retrieve the value. Default is the string value to return if the:

Section does not exist.

Key does not exist.

Data value for the key is not assigned.

C++ Examples:

Copy Code

/*
This example demonstrates the usage of Ini files in order to store
and load form configuration between sessions. Example assumes
a RadioGroup and two buttons are present on the main form.
*/
void __fastcall TForm2::btStoreClick(TObject *Sender)
{
    /* Open an instance */
    TCustomIniFile* SettingsFile = OpenIniFileInstance();

    // Store current form properties to be used in later sessions.
    try
    {
        SettingsFile->WriteInteger (Name, "Top", Top);
        SettingsFile->WriteInteger (Name, "Left", Left);
        SettingsFile->WriteInteger (Name, "Width", Width);
        SettingsFile->WriteInteger (Name, "Height", Height);
        SettingsFile->WriteString  (Name, "Caption", Caption);
        SettingsFile->WriteBool    (Name, "InitMax", WindowState == wsMaximized );
    }
    catch(Exception* e)
    {
    }

    delete SettingsFile;
}

void __fastcall TForm2::btLoadClick(TObject *Sender)
{
    /* Open an instance */
    TCustomIniFile* SettingsFile = OpenIniFileInstance();

    try
    {
        /*
        Read all saved values from the last session. The section name
        is the name of the form. Also use form's properties as defaults
        */
        Top     = SettingsFile->ReadInteger(Name, "Top", Top );
        Left    = SettingsFile->ReadInteger(Name, "Left", Left );
        Width   = SettingsFile->ReadInteger(Name, "Width", Width );
        Height  = SettingsFile->ReadInteger(Name, "Height", Height );
        Caption = SettingsFile->ReadString (Name, "Caption", Caption);

        // Load last window state
        if (SettingsFile->ReadBool(Name, "InitMax", WindowState == wsMaximized))
            WindowState = wsMaximized;
        else
            WindowState = wsNormal;
    }
    catch(Exception* e)
    {
    }

    delete SettingsFile;
}

TCustomIniFile* __fastcall TForm2::OpenIniFileInstance()
{
    /*
    Open/create a new INI file that has the same name as our executable
    only with the INI extension.
    */

    switch (RadioGroup1->ItemIndex)
    {
        case 0:
            /* Registry mode selected: in HKEY_CURRENT_USER\Software\... */
            return new TRegistryIniFile(String("Software\\") + Application->Title);
        case 1:
            /* Ini file mode selected */
            return new TIniFile(ChangeFileExt(Application->ExeName, ".INI"));
        case 2:
            /* Memory based Ini file mode selected */
            return new TMemIniFile(ChangeFileExt(Application->ExeName, ".INI"));
      }
}

Delphi Examples:

Copy Code

{
This example demonstrates the use of Ini files in order to store
and load form configurations between sessions. This example requires
a RadioGroup and two buttons.
}
procedure TForm2.btLoadClick(Sender: TObject);
var
  SettingsFile : TCustomIniFile;
begin
  { Open an instance }
  SettingsFile := OpenIniFileInstance();

  try
    {
    Read all saved values from the last session. The section name
    is the name of the form. Also use form's properties as defaults
    }
    Top     := SettingsFile.ReadInteger(Name, 'Top', Top );
    Left    := SettingsFile.ReadInteger(Name, 'Left', Left );
    Width   := SettingsFile.ReadInteger(Name, 'Width', Width );
    Height  := SettingsFile.ReadInteger(Name, 'Height', Height );
    Caption := SettingsFile.ReadString (Name, 'Caption', Caption);

    { Load last window state }
    case SettingsFile.ReadBool(Name, 'InitMax', WindowState = wsMaximized) of
      true : WindowState := wsMaximized;
      false: WindowState := wsNormal;
    end;

  finally
    SettingsFile.Free;
  end;
end;

procedure TForm2.btStoreClick(Sender: TObject);
var
  SettingsFile: TCustomIniFile;
begin
  { Open an instance }
  SettingsFile := OpenIniFileInstance();

  {
  Store current form properties to be used in later sessions.
  }
  try
    SettingsFile.WriteInteger (Name, 'Top', Top);
    SettingsFile.WriteInteger (Name, 'Left', Left);
    SettingsFile.WriteInteger (Name, 'Width', Width);
    SettingsFile.WriteInteger (Name, 'Height', Height);
    SettingsFile.WriteString  (Name, 'Caption', Caption);
    SettingsFile.WriteBool    (Name, 'InitMax', WindowState = wsMaximized );
    SettingsFile.WriteDateTime(Name, 'LastRun', Now);
  finally
    SettingsFile.Free;
  end;

end;

function TForm2.OpenIniFileInstance: TCustomIniFile;
begin
  {
  Open/create a new INI file that has the same name as our executable
  only with the INI extension.
  }

  case RadioGroup1.ItemIndex of
    0:
      begin
        { Registry mode selected: in HKEY_CURRENT_USER\Software\... }
        Result := TRegistryIniFile.Create('Software\' + Application.Title);
      end;
    1:
      begin
        { Ini file mode selected }
        Result := TIniFile.Create(ChangeFileExt(Application.ExeName, '.INI'));
      end;
    2:
      begin
        { Memory based Ini file mode selected }
        Result := TMemIniFile.Create(ChangeFileExt(Application.ExeName, '.INI'));
      end;
  end;
end;