TMemIniFile Class

TMemIniFile enables buffered storage and retrieval of application-specific information and settings in an INI file.

Pascal

TMemIniFile = class(TCustomIniFile);

C++

class TMemIniFile : public TCustomIniFile;

File

IniFiles

Description

Use TMemIniFile to store and retrieve application-specific information and settings in a Windows INI file. An INI file stores information in logical groupings, called "sections." Within each section, actual data values are stored in named keys. Keys take the form:

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<keyname>=<value>

TMemIniFile buffers all changes to the INI file. The INI file is read once, when the object is first created. Data from the INI file is stored in nested string lists. Each section in the INI file occupies one element in the top-most string list, and each element in this may itself contain a string list. Each element in each of the contained string list represents a key within the section. After the data is read, any changes to the data are stored in memory. To write the data from memory back to the associated INI file, call the UpdateFile method.

All TMemIniFile methods to read, write, and erase sections, keys, and values operate on the in-memory copy of the INI file.

C++ Examples:

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/*
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:

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{
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;