Background
I've been using Win32_DiskDrive to find flash memory (usb pens, SD cards, etc.), but after some tests on other computers I noticed that they weren't always discovered. So I am using Win32_LogicalDisk and since it has DriveType I don't have to associate with two classes (e.g. partition) to find first the drives then their drive letters.
The problem is that external harddrives are detected as DriveType 3 (Local Disk) in LogicalDisk and doesn't have 7 (Supports Removable Media) in Capabilities in DiskDrive. So I can't tell the difference between an internal and external drive.
Question
How do I tell the difference between an internal and an external harddrive using LogicalDisk (or DiskDrive if you really have to) or something third.
Alright. The question has been answered!
Here's the code, if anyone is interested.
program GetWMI_USBConnectedInfo;
{$APPTYPE CONSOLE}
uses
Windows,
Classes,
ActiveX,
Variants,
SysUtils,
WbemScripting_TLB, // Using the .pas supplied by the wrapper as it seems to be the XP version of 1.2
magwmi,
magsubs1;
function CheckType(Str: string): boolean;
var
I: Integer;
Str2: string;
begin
Result := False;
for I := 1 to Length(Str) - 1 do if Str[I] = '\' then begin
Str2 := Copy(Str, 1, I-1);
Str2 := LowerCase(Str2);
if (Str2 = 'usbstor') or (Str2 = 'flashmedia') then
Result := True;
Break;
end;
end;
procedure GetUSBDiskDriveInfo;
var
I, II, III: Integer;
Start, Stop, Freq: Int64;
instances, instances2, instances3: integer ;
WmiResults, WmiResults2, WmiResults3: T2DimStrArray ;
errstr: string ;
begin
QueryPerformanceFrequency(Freq);
QueryPerformanceCounter(Start);
try
MagWmiGetInfoEx('.', 'root\CIMV2', '', '', 'SELECT * FROM Win32_DiskDrive', WmiResults, instances, errstr);
for I := 1 to instances do begin
MagWmiGetInfoEx('.', 'root\CIMV2', '', '', 'ASSOCIATORS OF {Win32_DiskDrive.DeviceID=''' + WmiResults[I, 12] + '''} WHERE AssocClass = Win32_DiskDriveToDiskPartition', WmiResults2, instances2, errstr);
for II := 1 to instances2 do begin
MagWmiGetInfoEx('.', 'root\CIMV2', '', '', 'ASSOCIATORS OF {Win32_DiskPartition.DeviceID=''' + WmiResults2[II, 11] + '''} WHERE AssocClass = Win32_LogicalDiskToPartition', WmiResults3, instances3, errstr);
for III := 1 to instances3 do begin
if CheckType(WmiResults[I, 32]) or (Pos('7', WmiResults[I, 3])>0) then begin
Write(WmiResults3[III, 4]);
Write(WmiResults3[III, 39]);
Writeln;
end;
end;
WmiResults3 := nil;
end;
WmiResults2 := nil;
end;
WmiResults := nil;
except
Writeln;
Writeln('error: '+errstr);
end;
Writeln;
QueryPerformanceCounter(Stop);
if (Freq > 0) then
Writeln('It took ' + FormatFloat('0.#0', (Stop-Start) / Freq) + ' seconds to complete.');
end;
begin
try
CoInitialize(nil);
GetUSBDiskDriveInfo;
Readln;
CoUninitialize;
except
on E:Exception do begin
CoUninitialize;
Writeln(E.Classname, ': ', E.Message);
Readln;
end;
end;
end.
One more thing!
Call this a dirty hack or whatever, but I commented out this part of MagWmiGetInfoEx (line 298 in magwmi) in order to make it work:
// if Pos ('SELECT', Arg) = 1 then
wmiObjectSet := wmiServices.ExecQuery (Arg, 'WQL', wbemFlagReturnImmediately, nil)
// else
// wmiObjectSet := wmiServices.InstancesOf (Arg, wbemFlagReturnImmediately or
// wbemQueryFlagShallow, nil)
;