Inno Setup/Pascal Scripting - Casting Returning Nil - casting

Question

I'm trying to write some Pascal script for a installer I'm making with Inno Setup Compiler 5.5.1. I'm currently trying to add a custom wizard page that executes a command, taking user input from text fields (TEdit components). I defined the NextButtonClick function, and it checks that the Page ID is the custom page I defined and attempts to retrieve the user input from the field. When I get it from the components of the Page's Surface property, it gets returned as a TComponent. To get the next I need to cast it to a TEdit, so I tried casting it and it seems to be returning nil. Besides the scripting for Inno I've been doing for the past few days, I don't have much experience with Pascal, so I could possibly be doing something wrong. But I'd appreciate the help!
Here's the chunk of code giving me an issue for reference (with debugging lines left in):
function NextButtonClick(CurPageID: Integer): Boolean;
var
ResultCode: Integer;
CurrPage: TWizardPage;
Server : TComponent;
Server2: TEdit;
SurfacePage : TNewNotebookPage;
ServerStr : String;
begin
if CurPageID = 100 then
begin
CurrPage := PageFromID(100);
SurfacePage := CurrPage.Surface;
Server := SurfacePage.Controls[0];
Server2 := TEdit(Server); // RETURNS NIL HERE
if Server2 = nil then
MsgBox('', mbInformation, MB_OK);
ServerStr := Server2.Text;
MsgBox(ServerStr, mbInformation, MB_OK);
//ShellExec('', 'sqlcmd', '-S ' + ServerStr + ' -Q ":r setMemUsage.sql"', ExpandConstant('{app}') + '\sql', SW_SHOW, ewWaitUntilTerminated, ResultCode);
end;
Result := True;
end;

Answer 1

I can't simulate your problem. I've used this minimalistic code:
[Code]
var
CustomPageID: Integer;
procedure InitializeWizard;
var
EditBox: TEdit;
CustomPage: TWizardPage;
begin
CustomPage := CreateCustomPage(wpWelcome, '', '');
CustomPageID := CustomPage.ID;
EditBox := TEdit.Create(WizardForm);
EditBox.Parent := CustomPage.Surface;
end;
procedure CurPageChanged(CurPageID: Integer);
var
EditBox: TEdit;
Component: TComponent;
CustomPage: TWizardPage;
begin
if (CurPageID = CustomPageID) then
begin
CustomPage := PageFromID(CustomPageID);
Component := CustomPage.Surface.Controls[0];
if (Component is TEdit) then
begin
MsgBox('Controls[0] is assigned and is TEdit', mbInformation, MB_OK);
EditBox := TEdit(Component);
EditBox.Text := 'Hi, I''m just a modified edit text!';
end;
end;
end;