How do I use WMI with Delphi without drastically increasing the application's file size?

Question

I am using Delphi 2010, and when I created a console application that prints "Hello World", it takes 111 kb. If I want to query WMI with Delphi, I add WBEMScripting_TLB, ActiveX, and Variants units to my project. If I perform a simple WMI query, my executable size jumps to 810 kb. I

Is there anyway to query WMI without such a large addition to the size of the file? Forgive my ignorance, but why do I not have this issue with C++?

Here is my code:

program WMITest;

{$APPTYPE CONSOLE}

uses
  SysUtils,
  WBEMScripting_TLB,
  ActiveX,
  Variants;

function GetWMIstring(wmiHost, root, wmiClass, wmiProperty: string): string;
var
  Services: ISWbemServices;
  SObject: ISWbemObject;
  ObjSet: ISWbemObjectSet;
  SProp: ISWbemProperty;
  Enum: IEnumVariant;
  Value: Cardinal;
  TempObj: OLEVariant;
  loc: TSWbemLocator;
  SN: string;
  i: integer;
begin
  Result := '';
  i := 0;
  try
    loc := TSWbemLocator.Create(nil);
    Services := Loc.ConnectServer(wmiHost, root {'root\cimv2'}, '', '', '', '',
      0, nil);
    ObjSet := Services.ExecQuery('SELECT * FROM ' + wmiClass, 'WQL',
      wbemFlagReturnImmediately and wbemFlagForwardOnly, nil);
    Enum := (ObjSet._NewEnum) as IEnumVariant;
    if not VarIsNull(Enum) then
      try
        while Enum.Next(1, TempObj, Value) = S_OK do
        begin
          try
            SObject := IUnknown(TempObj) as ISWBemObject;
          except SObject := nil;
          end;
          TempObj := Unassigned;
          if SObject <> nil then
          begin
            SProp := SObject.Properties_.Item(wmiProperty, 0);
            SN := SProp.Get_Value;
            if not VarIsNull(SN) then
            begin
              if varisarray(SN) then
              begin
                for i := vararraylowbound(SN, 1) to vararrayhighbound(SN, 1) do
                  result := vartostr(SN[i]);
              end
              else
                Result := SN;
              Break;
            end;
          end;
        end;
        SProp := nil;
      except
        Result := '';
      end
    else
      Result := '';
    Enum := nil;
    Services := nil;
    ObjSet := nil;
  except
    on E: Exception do
      Result := e.message;
  end;
end;

begin
  try
    WriteLn('hello world');
    WriteLn(GetWMIstring('.', 'root\CIMV2', 'Win32_OperatingSystem',
      'Caption'));
    WriteLn('done');

  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

UPDATE: When I compile the following sample from MSDN with Microsoft Visual C++ 2008 (console application), it is 76 kb.

Answer 1

@Mick, you can access the WMI without import the WBEMScripting from Delphi, using the IBindCtx and IMoniker interfaces.

Check this simple code (Tested in Delphi 2010 and Windows 7), the exe file size is 174 kb.

program WmiTest;

{$APPTYPE CONSOLE}


uses
  SysUtils
  ,ActiveX
  ,ComObj
  ,Variants;


function GetWMIstring(wmiHost, root, wmiClass, wmiProperty: string): string;
var
  objWMIService : OLEVariant;
  colItems      : OLEVariant;
  colItem       : OLEVariant;
  oEnum         : IEnumvariant;
  iValue        : LongWord;

  function GetWMIObject(const objectName: String): IDispatch;
  var
    chEaten: Integer;
    BindCtx: IBindCtx;//for access to a bind context
    Moniker: IMoniker;//Enables you to use a moniker object
  begin
    OleCheck(CreateBindCtx(0, bindCtx));
    OleCheck(MkParseDisplayName(BindCtx, StringToOleStr(objectName), chEaten, Moniker));//Converts a string into a moniker that identifies the object named by the string
    OleCheck(Moniker.BindToObject(BindCtx, nil, IDispatch, Result));//Binds to the specified object
  end;

begin
  objWMIService := GetWMIObject(Format('winmgmts:\\%s\%s',[wmiHost,root]));
  colItems      := objWMIService.ExecQuery(Format('SELECT * FROM %s',[wmiClass]),'WQL',0);
  oEnum         := IUnknown(colItems._NewEnum) as IEnumVariant;
  while oEnum.Next(1, colItem, iValue) = 0 do 
  begin
     Result:=colItem.Properties_.Item(wmiProperty, 0); //you can improve this code  ;) , storing the results in an TString.
  end;
end;

begin
 try
    CoInitialize(nil);
    try         
      WriteLn(GetWMIstring('.', 'root\CIMV2', 'Win32_OperatingSystem','Caption'));
      Readln;
    finally
    CoUninitialize;
    end;
 except
    on E:Exception do
    Begin
        Writeln(E.Classname, ': ', E.Message);
        Readln;
    End;
  end;
end.