Ask for a drive to install

From ISXKB

This code was provided by Abel G. Perez
This code was based on the old ISXKB CHM article and the Inno newsgroup and I believe it works only in Inno v5+. I also made some modifications to improve it.

[Setup]
AppName=My Program
AppVerName=My Program version 1.5
DefaultDirName={sd}\My Program
DefaultGroupName=My Program
UninstallDisplayIcon={app}\MyProg.exe
Compression=lzma
SolidCompression=true
OutputDir=.
DisableProgramGroupPage=true
UsePreviousGroup=false
ShowLanguageDialog=yes

[Files]
;test file
Source: RP4801_manual.pdf; DestDir: {app} ; AfterInstall: MyAfterInstall2('{app}\B\MYFILE.TXT')


[Messages]
SelectDirBrowseLabel=To continue, click Next. If you would like to select a different drive, choose from the list.

[Code]

var
	// combo box for drives
	cbDrive : TComboBox ;
	// array of strings that stores the drive letters
	DrvLetters: array of String;

function GetDriveType( lpDisk: String ): Integer;
external 'GetDriveTypeA@kernel32.dll stdcall';

function GetLogicalDriveStrings( nLenDrives: LongInt; lpDrives: String ): Integer;
external 'GetLogicalDriveStringsA@kernel32.dll stdcall';

const
  DRIVE_UNKNOWN = 0;     // The drive type cannot be determined.
  DRIVE_NO_ROOT_DIR = 1; // The root path is invalid. For example, no volume is mounted at the path.
  DRIVE_REMOVABLE = 2;   // The disk can be removed from the drive.
  DRIVE_FIXED = 3;       // The disk cannot be removed from the drive.
  DRIVE_REMOTE = 4;      // The drive is a remote (network) drive.
  DRIVE_CDROM = 5;       // The drive is a CD-ROM drive.
  DRIVE_RAMDISK = 6;     // The drive is a RAM disk.


// function to convert disk type to a regonizable string. This piece needs translation
// to other languages
function DriveTypeString( dtype: Integer ): String ;
begin
  case dtype of
    DRIVE_NO_ROOT_DIR : Result := 'Root path invalid';
    DRIVE_REMOVABLE : Result := 'Removable';
    DRIVE_FIXED : Result := 'Fixed';
    DRIVE_REMOTE : Result := 'Network';
    DRIVE_CDROM : Result := 'CD-ROM';
    DRIVE_RAMDISK : Result := 'Ram disk';
  else
    Result := 'Unknown';
  end;
end;

// change folder accordigly to the drive letter selected
procedure cbDriveOnClick(Sender: TObject);
begin
	WizardForm.DirEdit.Text := DrvLetters[ cbDrive.ItemIndex ] + 'My program';
end;

procedure FillCombo();
var
  n: Integer;
  drivesletters: String; lenletters: Integer;
  drive: String;
  disktype, posnull: Integer;
  sd: String;
  
begin
  //get the system drive
  sd := UpperCase(ExpandConstant('{sd}'));

  //get all drive letters of the system
  drivesletters := StringOfChar( ' ', 64 );
  lenletters := GetLogicalDriveStrings( 63, drivesletters );
  SetLength( drivesletters , lenletters );

  drive := '';
  n := 0;
  while ( (Length(drivesletters) > 0) ) do
  begin
    posnull := Pos( #0, drivesletters );
  	if posnull > 0 then
  	begin
      drive:= UpperCase( Copy( drivesletters, 1, posnull - 1 ) );

      // get number type of disk
      disktype := GetDriveType( drive );


      // you can add various types of checks here to limit the types of drives that
      // are displayed to the user. in this example we add a drive only if is not a
      // removable drive (ie floppy, USB key, etc). you may add whatever limitations
      // you need in the next IF statement
      if ( not ( disktype = DRIVE_REMOVABLE ) ) then
      begin

		    cbDrive.Items.Add( drive + '   [' + DriveTypeString( disktype ) + ']' )

        SetArrayLength(DrvLetters, N+1);
        DrvLetters[n] := drive;

        // default select C: Drive (not very wise since the users system drive may not be C: or they
        // may not even have a C: drive
        //if ( Copy(drive,1,2) = 'C:' ) then cbDrive.ItemIndex := n;
        // instead default it to the users system drive
        if ( Copy(drive,1,2) = sd ) then cbDrive.ItemIndex := n;
        
        n := n + 1;
      end

  	  drivesletters := Copy( drivesletters, posnull+1, Length(drivesletters));
  	end
  end;

  cbDriveOnClick( cbDrive );

end;


procedure InitializeWizard();
begin

	// create the combo box for drives
	cbDrive:= TComboBox.Create(WizardForm.SelectDirPage);
    with cbDrive do
    begin
      Parent := WizardForm.DirEdit.Parent;

      Left := WizardForm.DirEdit.Left;
      Top := WizardForm.DirEdit.Top + WizardForm.DirEdit.Height * 2;
      Width := WizardForm.DirEdit.Width;

      Style := csDropDownList;
    end;

	// hide the Browse button
	WizardForm.DirBrowseButton.Visible := false;

	// Edit box for folder is non-editable
	WizardForm.DirEdit.Enabled := false;

	// fill combo box with Drives
	FillCombo;

	// set the event on combo change
	cbDrive.OnClick := @cbDriveOnClick ;
end;

//test function
procedure MyAfterInstall2(FileName: String);
begin
  MsgBox('Just installed ' + FileName + ' as ' + CurrentFileName + '.', mbInformation, MB_OK);
end;

See also

• GetDriveType ()
• GetLogicalDriveStrings ()
• Support Classes Reference in Inno Setup's help file online