[LuisAlf::]

Hola....

Intente insertar las funciones que vienen en la pagina para expulsar memorias usb en un proyecto y no me hacen nada cuando las mando a llamar...

Código Delphi [-]
unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
{$R *.dfm}
function OpenVolume(ADrive: char): THandle;
var
  RootName, VolumeName: string;
  AccessFlags: DWORD;
begin
  RootName := ADrive + ':\'; // ADrive + ':\' kills the syntax highlighting
  case GetDriveType(PChar(RootName)) of
    DRIVE_REMOVABLE:
      AccessFlags := GENERIC_READ or GENERIC_WRITE;
    DRIVE_FIXED:       //Añado el tipo FIXED Para q actue sobre discos USB
      AccessFlags := GENERIC_READ or GENERIC_WRITE;
    DRIVE_CDROM:
      AccessFlags := GENERIC_READ;
  else
    Result := INVALID_HANDLE_VALUE;
    exit;
  end;
  VolumeName := Format('\\.\%s:', [ADrive]);
  Result := CreateFile(PChar(VolumeName), AccessFlags, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
  if Result = INVALID_HANDLE_VALUE then RaiseLastOSError;
end;
  //---------------------------//
function LockVolume(AVolumeHandle: THandle): boolean;
const
  LOCK_TIMEOUT = 10 * 1000; // 10 Seconds
  LOCK_RETRIES = 20;
  LOCK_SLEEP = LOCK_TIMEOUT div LOCK_RETRIES;
// #define FSCTL_LOCK_VOLUME CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 6, METHOD_BUFFERED, FILE_ANY_ACCESS)
  FSCTL_LOCK_VOLUME = (9 shl 16) or (0 shl 14) or (6 shl 2) or 0;
var
  Retries: integer;
  BytesReturned: Cardinal;
begin
  for Retries := 1 to LOCK_RETRIES do
  begin
    Result := DeviceIoControl(AVolumeHandle, FSCTL_LOCK_VOLUME, nil, 0, nil, 0, BytesReturned, nil);
    if Result then break;
    Sleep(LOCK_SLEEP);
  end;
end;
  //---------------------------//
function DismountVolume(AVolumeHandle: THandle): boolean;
const
// #define FSCTL_DISMOUNT_VOLUME CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 8, METHOD_BUFFERED, FILE_ANY_ACCESS)
  FSCTL_DISMOUNT_VOLUME = (9 shl 16) or (0 shl 14) or (8 shl 2) or 0;
var
  BytesReturned: Cardinal;
begin
  Result := DeviceIoControl(AVolumeHandle, FSCTL_DISMOUNT_VOLUME, nil, 0, nil, 0, BytesReturned, nil);
  if not Result then RaiseLastOSError;
end;
  //---------------------------//
function PreventRemovalOfVolume(AVolumeHandle: THandle; APreventRemoval: boolean): boolean;
const
// #define IOCTL_STORAGE_MEDIA_REMOVAL CTL_CODE(IOCTL_STORAGE_BASE, 0x0201, METHOD_BUFFERED, FILE_READ_ACCESS)
  IOCTL_STORAGE_MEDIA_REMOVAL = ($2d shl 16) or (1 shl 14) or ($201 shl 2) or 0;
type
  TPreventMediaRemoval = record
    PreventMediaRemoval: BOOL;
  end;
var
  BytesReturned: Cardinal;
  PMRBuffer: TPreventMediaRemoval;
begin
  PMRBuffer.PreventMediaRemoval := APreventRemoval;
  Result := DeviceIoControl(AVolumeHandle, IOCTL_STORAGE_MEDIA_REMOVAL,
    @PMRBuffer, SizeOf(TPreventMediaRemoval), nil, 0, BytesReturned, nil);
  if not Result then
    RaiseLastOSError;
end;
  //---------------------------//
function AutoEjectVolume(AVolumeHandle: THandle): boolean;
const
// #define IOCTL_STORAGE_EJECT_MEDIA CTL_CODE(IOCTL_STORAGE_BASE, 0x0202, METHOD_BUFFERED, FILE_READ_ACCESS)
//  IOCTL_STORAGE_EJECT_MEDIA = ($2d shl 16) or (1 shl 14) or ($202 shl 2) or 0;
  IOCTL_STORAGE_EJECT_MEDIA: Cardinal      = $002d4808;
  IOCTL_STORAGE_EJECTION_CONTROL: Cardinal = $002d0940;
var
  BytesReturned: Cardinal;
begin
  Result := DeviceIoControl(AVolumeHandle, IOCTL_STORAGE_EJECT_MEDIA, nil, 0, nil, 0, BytesReturned, nil);
  if not Result then RaiseLastOSError;
end;
  //---------------------------//
function EjectVolume(ADrive: char): boolean;
var
  VolumeHandle: THandle;
begin
  Result := FALSE;
  // Open the volume
  VolumeHandle := OpenVolume(ADrive);
  if VolumeHandle = INVALID_HANDLE_VALUE then  exit;
  try
    // Lock and dismount the volume
    if LockVolume(VolumeHandle) and DismountVolume(VolumeHandle) then
    begin
      // Set prevent removal to false and eject the volume
      if PreventRemovalOfVolume(VolumeHandle, FALSE) then Result := AutoEjectVolume(VolumeHandle);
    end;
  finally
    // Close the volume so other processes can use the drive
    CloseHandle(VolumeHandle);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var letra: char;
begin
      for  letra:='a' to 'z' do
      begin
          if GetDriveType(PChar(letra+':\'))= DRIVE_REMOVABLE then
          begin
          exit;
          end;
      end;
ejectvolume(letra);
end;
end.

Que estoy haciendo mal???

SALUDOS