delphi - 在不大幅增加应用程序文件大小的情况下，如何在Delphi中使用WMI？

我正在使用Delphi 2010，当我创建一个打印“ Hello World”的控制台应用程序时，它需要111 kb。如果要使用Delphi查询WMI，请将WBEMScripting_TLB，ActiveX和Variants单位添加到项目中。如果我执行简单的WMI查询，我的可执行文件大小将跳到810 kb。一世

无论如何，是否在不增加文件大小的情况下查询WMI？原谅我的无知，但是为什么我的C ++没有这个问题？

这是我的代码：

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.

更新：
当我使用Microsoft Visual C ++ 2008（控制台应用程序）编译following sample from MSDN时，它是76 kb。

最佳答案

@Mick，您可以使用IBindCtx和IMoniker接口访问WMI，而无需从Delphi导入WBEMScripting。

检查此简单代码（在Delphi 2010和Windows 7中测试），exe文件大小为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.

关于delphi - 在不大幅增加应用程序文件大小的情况下，如何在Delphi中使用WMI？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/2761328/