Delphi: Creating a TComboBox in a dynamically created form at runtime

Delphi: Creating a TComboBox in a dynamically created form at runtime

Okay, I am working in a project that was originally done in D7. And I am
doing double duty here as I am working on fixing bugs in the original code
and attempting to port it over to XE3/4. Kinda hard when the original
author used some none-open source kits for the project.
But anyways, the app is a scripting/macroing program. As part of the
custome scripting/macroing language. There is a ability to create very
simple basic forms for user input. The forms are created dynamically at
runtime based on the script/macro the script/macro author has created. I
have already fixed some bugs in the code for the creation of the forms.
But, there is one that I just can not figure out.
When creating a TComboBox for the parent form and setting the Text
property AT component creation. The text in the Text property is not
displayed.
Here is the code to create the form:
procedure CreateForm(var wFrm: TForm; sName: String);
var
iLoop, iPos, iLen: Integer;
iFormHeight, iFormWidth: Integer;
lh, hresult1, hresult2: Integer;
sWork, sWork2, sLine, CmdName: String;
lstForm, lst: TStringList;
pnl: TPanel;
begin
iFormHeight := 80;
iFormWidth := 400;
hresult1 := 0;
lst := TStringList.Create;
iLoop := lstForms.IndexOf(Trim(UpperCase(sName)));
if iLoop < 0 then
begin
AbortError('Form "' + sName + '" could not be found!');
Exit;
end;
lstForm := TStringList(lstForms.Objects[iLoop]);
for iLoop := 0 to lstForm.Count - 1 do
begin
sLine := lstForm[iLoop];
iPos := Pos('=', sLine);
iLen := Length(sLine);
if iPos = 0 then
continue;
CmdName := Uppercase(Trim(Copy(sLine, 1, iPos - 1)));
sWork2 := Trim(Copy(sLine, iPos + 1, iLen));
if CmdName = 'FORMCAPTION' then
begin
with wfrm do
begin
Caption := Trim(Copy(sLine, iPos + 1, iLen));
Name := Trim(sName);
Height := iFormHeight;
Width := iFormWidth;
Tag := 10;
BorderStyle := bsSizeable;
BorderIcons := [biSystemMenu];
Position := poDesktopCenter;
pnl := TPanel.Create(wfrm);
with pnl do
begin
Parent := wfrm;
Caption := '';
Align := alBottom;
BevelInner := bvNone;
BevelOuter := bvNone;
Height := 30;
end;
with TButton.Create(wfrm) do
begin
Parent := pnl;
Caption := '&OK';
Default := True;
ModalResult := mrOK;
Left := 235;
Top := 0;
end;
with TButton.Create(wfrm) do
begin
Parent := pnl;
Caption := '&Cancel';
Cancel := True;
ModalResult := mrCancel;
Left := 310;
Top := 0;
end;
pnl := TPanel.Create(wfrm);
with pnl do
begin
Parent := wfrm;
Caption := '';
Align := alClient;
BevelInner := bvRaised;
BevelOuter := bvNone;
BorderWidth := 5;
end;
end;
end
else
begin
lst.Clear;
StringToList(sWork2, lst, ':');
if UpperCase(lst[0]) = 'EDITBOX' then
CreateEditBox
else if UpperCase(lst[0]) = 'CHECKBOX' then
CreateCheckBox
else if UpperCase(lst[0]) = 'COMBOBOX' then
CreateComboBox
else if UpperCase(lst[0]) = 'LABEL' then
CreateLabel;
end;
end;
with wfrm do
begin
if hresult1 > 1 then
hresult2 := 5
else
hresult2 := 9;
Tag := Tag + hresult2;
Height := Height + hresult2;
end;
lst.Free;
end;
And here is the specific code to create the TComboBox, w/ TLabel, for the
form:
procedure CreateComboBox;
var
iPos: Integer;
begin
with TLabel.Create(wfrm) do
begin
Parent := pnl;
Caption := lst[1];
Left := 15;
if hresult1 > 1 then
hresult2 := 5 * hresult1
else
hresult2 := 3 * hresult1;
Top := wfrm.Tag + hresult2;
Name := 'lbl' + CmdName;
Width := 150;
WordWrap := True;
AutoSize := True;
lh := Height;
end;
hresult1 := Trunc(lh/13);
with TComboBox.Create(wfrm) do
begin
Parent := pnl;
Left := 170;
Width := 200;
if hresult1 > 1 then
hresult2 := 5 * hresult1
else
hresult2 := 3 * hresult1;
Top := wfrm.Tag + hresult2;
Style := csDropDownList;
Name := UpperCase(CmdName);
Text := 'Test Text';
sWork := lst[3];
lst.Clear;
StringToList(sWork, lst, ',');
for iPos := 0 to lst.Count - 1 do
lst[iPos] := lst[iPos];
Items.Assign(lst);
// ItemIndex := 0;
end;
wfrm.Tag := wfrm.Tag + ((hresult1 * 13)+ 13);
wfrm.Height := wfrm.Height + ((hresult1 * 13)+ 13);
TComboBox(wfrm
end;
NOTE: the above procedure is a child procedure of the CreateForm procedure.
The app uses TStringList lists to store the form definition at
script/macro runtime. Then the above code retrieves that information to
create to form when the author wants the form to be shown. And then
creates the form and places the form object into another temporary
TStringList list prior to being shown. This is done so that when the user
runs the script/macro and enters the information/settings as requested in
the form. The author may retrieve the requested information/settings from
the form before the form is destroyed.
The form is deleted (if previously created) from tmp TStringList list,
created, stored in tmp TStringList list, and shown modally with the
following code:
iPos := lstForms.IndexOf(UpperCase(sWVar2));
if iPos < 0 then
begin
AbortError('Could not find form "' + Trim(sWVar2) + '" defined!');
Exit;
end;
iPos := lstFormsTMP.IndexOf(UpperCase(sWVar2));
if iPos > -1then
begin
TForm(lstFormsTMP.Objects[iPos]).Free;
lstFormsTMP.Delete(iPos);
frm.Free;
iPos := lstFormsTMP.IndexOf(UpperCase(sWVar2));
if iPos > -1 then
begin
AbortError('Form "' + Trim(sWVar2) + '" was not removed from the
lstFormsTMP TStringList.');
Exit;
end;
end;
frm := TForm.Create(frmMain);
CreateForm(frm, sWVar2);
lstFormsTMP.AddObject(Uppercase(sWVar2), frm);
end;
iPos := lstFormsTMP.IndexOf(UpperCase(sWVar2));
if iPos < 0 then
begin
AbortError('Could not find form "' + Trim(sWVar2) + '" defined!');
Exit;
end;
hndHold := SwitchToHandle(frmMain.Handle);
try
Result := TForm(lstFormsTMP.Objects[iPos]).ShowModal = mrOK;
finally
SwitchToHandle(hndHold);
end;
With the above sets of code the form defined in the running script is
created and shown, without to many bugs/errors. But, even though I have
hardcoded the text for the TComboBox.Text property. It is not shown. Can
anyone shed some lite on why this is the case for me? All other form
components, TCheckBox, TEditBox, TLabel, are displayed without any issues,
so far. It is just the TComboBox that is causing me to scratch my head in
confusion.
NOTE: Eventually the TComboBox.Text property will be dynamically set based
on the authors setting for that property in the form component's
definition.
Thanks in advance.