I am still trying to successfully call methods in a VB6 automation object
that has array arguments. In VB, the method takes dynamic arrays of Single and
Long Integer.
In Delphi 2.0, I tried using the OLECreateArray function with types
varSingle and varInteger, as well as with varVariant (as per a previous suggestion).
In all cases, I get an OLE exception error indicating an argument type mismatch.
I have no trouble creating an instance of the object, or calling
methods that do not require arrays. Simple functions and methods work fine.
I have appended example code to this message. The automation object,
for those who might have a copy, is the server that comes with the TC-2000 stock
data service from Worden Bros. They provide info on VB, but not on Delphi. I have
been able to call the functions from VBA in Excel, but would much prefer to work in
Delphi.
Any help would be appreciated.
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls,
Forms, Dialogs, Grids, StdCtrls, OleAuto;
type
TForm1 = class(TForm)
Button1: TButton;
StringGrid1: TStringGrid;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
Server: Variant;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
begin
{ This code works fine, runs with no problems.
Initializes the server as it should.
The Server object was written in VB, version 6 }
StringGrid1.Cells[1, 1] := 'Creating Server Object';
Server := CreateOleObject('TC2000Dev.cTC2000');
StringGrid1.Cells[1, 2] := Server.TCEnabled;
StringGrid1.Cells[1, 3] := Server.GetVersion;
StringGrid1.Cells[1, 4] := Server.GetRevision;
StringGrid1.Cells[1, 5] := 'Server Created';
end;
procedure TForm1.Button2Click(Sender: TObject);
var
num, znum, opn, hi, lo, cls, vol, dt: Variant;
begin
{ This code attempts to retrieve data from the server.
It fails when the GetPrices method is called. }
opn := VarArrayCreate([1, 10], varVariant);
hi := VarArrayCreate([1, 10], varVariant);
lo := VarArrayCreate([1, 10], varVariant);
cls := VarArrayCreate([1, 10], varVariant);
vol := VarArrayCreate([1, 10], varVariant);
dt := VarArrayCreate([1, 10], varVariant);
num := 1234;
znum := 0;
{ The GetPrices method fails at run time with a Delphi
exception of type EOleError indicating a "type mismatch".
I have tried VarArrayCreate with varSingle and varInteger
to mimic the VB code shown below, but still get the same
error message. The server is the automation object that
comes with the TC-2000 Worden Bros. stock data service. }
Server.GetPrices(num, opn, hi, lo, cls, vol, dt, znum);
With StringGrid1 Do Begin
Cells[2, 1] := FloatToStr(cls[2]);
Cells[2, 2] := FloatToStr(vol[2]);
Cells[2, 3] := IntToStr(VarArrayHighBound(cls, 1));
Cells[2, 4] := IntToStr(VarArrayLowBound(cls, 1));
End;
Server := Unassigned;
end;
{
In Excel's VB, the following code works fine:
Dim Server As Object
Dim opn() As Single, hi() As Single, lo() As Single
Dim cls() As Single, vol() As Long, dt() As Long
Dim znum As Long, num As Long
.
.
Sub Button1Click()
Set Server = ...
.
Server.GetPrices num, opn(), hi(), lo(),
cls(), vol(), dt(), znum
.
. display the data...
End Sub
}
end.
