Well after a few minutes of finger bluring action last night I got it
working with MethodAccess. I've included an example below -
{-------------------------------------------------------------}
type
TMathOperation = function (const iVar1, iVar2 : integer) : integer of
object;
TBasicMath = class(TObject)
private
protected
public
class function Execute(const sOperation : string; const iVar1, iVar2 :
integer) : integer;
published
function Add(const iVar1, iVar2 : integer) : integer;
function Subtract(const iVar1, iVar2 : integer) : integer;
function Multiply(const iVar1, iVar2 : integer) : integer;
function Divide(const iVar1, iVar2 : integer) : integer;
end;
implementation
{$R *.DFM}
class function TBasicMath.Execute(const sOperation : string; const iVar1,
iVar2 : integer) : integer;
var
ABasicMath : TBasicMath;
AMathOp : TMathOperation;
AMathMethod : TMethod;
begin
ABasicMath := TBasicMath.Create;
try
AMathMethod.Code := ABasicMath.MethodAddress(sOperation);
AMathMethod.Data := ABasicMath;
AMathOp := TMathOperation(AMathMethod);
assert(assigned(AMathOp));
Result := AMathOp(iVar1, iVar2)
finally
ABasicMath.Free;
end;
end;
function TBasicMath.Add(const iVar1, iVar2 : integer) : integer;
begin
Result := iVar1 + iVar2;
end;
function TBasicMath.Subtract(const iVar1, iVar2 : integer) : integer;
begin
Result := iVar1 - iVar2;
end;
function TBasicMath.Multiply(const iVar1, iVar2 : integer) : integer;
begin
Result := iVar1 * iVar2;
end;
function TBasicMath.Divide(const iVar1, iVar2 : integer) : integer;
begin
Result := iVar1 div iVar2;
end;
{-------------------------------------------------------------}
The usage for it would be something like this -
Edit1.Text := IntToStr(TBasicMath.Execute('Divide', 81, 9));
Hopefully its useful for someone.
Cheers,
Nahum.
> -----Original Message-----
> From: Stephen Bertram [mailto:[EMAIL PROTECTED]]
> Sent: Friday, April 06, 2001 09:33 AM
> To: Multiple recipients of list delphi
> Subject: RE: [DUG]: How to Do This
>
>
> Further to my earlier post I found some of the code I used to
> call functions
> by name at runtime and have put this below. The basic idea
> (and the bulk of
> the code) for this was given to me by a C programmer.
>
> If anyone has a neater way to access methods at runtime I
> would love to see
> it.
>
> Stephen
>
> In the Application units
> -----------------------------------
> ...
> uses dispatch;
> ...
> var
> Req : TStringList;
> LocalVariable : String;
> ...
> // To call a function - initialize the parameters and call CallFnc
> Req.Clear;
> Req.Add('Param1=XX');
> Req.Add('Param2=1');
> LocalVariable := CallFnc('FunctionName',Req);
> ...
> initialization
> // Add all functions to the FnList
> FnList.AddObject('<FunctionName>=<whatever ID you want to
> use>',@FunctionName);
> end.
>
>
> Function calling unit
> ------------------------------------
> unit dispatch;
>
> interface
>
> uses Classes, sysutils;
>
> type
> TCallFn = function(req : TStringList) : string;
>
> function CallFnc (FncName : string; Req : TStringList):string;
>
> var
> FnList : tstringlist;
>
> implementation
>
> function CallFnc (FncName : string; Req : TStringList):string;
> begin
> if Fnlist.indexofname(FncName) = -1 then
> Result := ' Function ' + FncName + ' not found '
> else
> Result := TCallFn (FnList.objects[
> FnList.indexofname(FncName)])(Req);
> end;
>
> initialization
> FnList := TStringList.Create;
> finalization
> FnList.Free;
> end.
> --------------------------------------------------------------
> -------------
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