In my application (Delphi), I need to list all the USB storage devices. These can be either flash memory sticks or external storage drives.
There is a Jvcl component JvDriveCombo, and it has the DriveType property - the problem is if I select 'DriveType := Fixed' then in addition to the external drive, it also lists the internal drives (C:\, D:\ etc) . However, I only want to list the external drives.
I believe there is DeviceIoControl function (I saw it on MSDN) but I have no idea of how to use it.
I wonder if anyone can help me with the proper way / code to list USB storage devices?
Thanks.
EDIT:
I just found some sample code and am posting it here:
uses .... jwawinbase, JwaWinIoctl;
procedure TForm1.Button1Click(Sender: TObject);
var
DriveCmdStr: string;
DriveHandle: THandle;
ADriveLetter: string;
hp: STORAGE_HOTPLUG_INFO;
rlen: DWORD;
begin
ADriveLetter := 'H';
DriveCmdStr := Format('\\.\%s:', [ADriveLetter]);
DriveHandle := CreateFile(PChar(DriveCmdStr), GENERIC_READ, FILE_SHARE_WRITE,
nil, OPEN_EXISTING, 0, 0);
if DriveHandle = INVALID_HANDLE_VALUE then
Exit;
DeviceIoControl(DriveHandle, IOCTL_STORAGE_GET_HOTPLUG_INFO, nil, 0, @hp,
SizeOf(hp), @rlen, nil);
CloseHandle(DriveHandle);
if hp.MediaRemovable then
showmessage('media removable');
end;
Now I would like to just know how to enumerate all the drive letters. Which is the most efficient function?