Custom page with radio buttons for one define - inno-setup

Question

I would like to create a custom Inno Setup page that will be displayed at the very beginning of installation, with 3 radio buttons to select from. That selection should set the value in #define BinVer. Currently I'm forced to make 3 separate installers, but I prefer to have just one with such feature. I'm setting it up like that for each exe:
#define BinVer "111111", in another compilation I change it to #define BinVer "222222", and finaly I have #define BinVer "333333" for the third compilation. I'm using this define in such situations li ke that:
procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
begin
case CurUninstallStep of
usPostUninstall:
begin
CreateDir(ExpandConstant('{app}\bin\{#BinVer}\files'));
end;
end;
end;
or
Source: "{#CompPath}\Folder\sed.exe"; DestDir: "{app}\bin\{#BinVer}\files\gui\unbound\"; Flags: deleteafterinstall
So far I have tried something like this, but it's just very beginning, not sure what to do next, I'm not that good with programming it:
[Code]
procedure InitializeWizard();
var
Page: TInputOptionWizardPage;
begin
Page := CreateInputOptionPage(wpWelcome, '', '', '', False, False);
Page.AddEx('Radio button 1', 0, True);
Page.AddEx('Radio button 2', 0, True);
Page.AddEx('Radio button 3', 0, True);
end;
Also tried something like that (but I don't know if this is correct way to achieve this, it's not even compiling without errors):
[Code]
var
BinVer: string;
function InitializeSetup(): Boolean;
var
Page: TInputOptionWizardPage;
begin
Page := CreateInputOptionPage(wpWelcome, 'Select BinVer', 'Select BinVer', '', False, False);
Page.Add('BinVer 1', '111111');
Page.Add('BinVer 2', '222222');
Page.Add('BinVer 3', '333333');
Page.DefaultValueIndex := 0; // initially select the first radio button
Result := True;
end;
function NextButtonClick(CurPageID: Integer): Boolean;
var
Page: TInputOptionWizardPage;
begin
Result := True;
if CurPageID = wpWelcome then
begin
Page := GetInputOptionPage(wpWelcome);
case Page.SelectedValueIndex of
0: BinVer := '111111';
1: BinVer := '222222';
2: BinVer := '333333';
end;
end;
end;

Answer 1

You cannot change a value of a preprocessor variable (used on compile-time) on runtime.
But you do not have to. You want to use the value on runtime from Pascal Code. And you already have the value stored to runtime Pascal variable (BinVer: string). So use that:
CreateDir(ExpandConstant('{app}\bin\' + BinVer + '\files'));
Though you do not really need to store the value to the global variable either. You can query the "InputOptionPage" when needed.
Example of full code, linking the selection to the [Files] section entry destination:
[Files]
Source: "{#CompPath}\Folder\sed.exe"; \
DestDir: "{app}\bin\{code:GetBinVer}\files\gui\unbound\"; \
Flags: deleteafterinstall
[Code]
var
InputOptionPage: TInputOptionWizardPage;
procedure InitializeWizard();
begin
InputOptionPage := CreateInputOptionPage(wpWelcome, '', '', '', False, False);
InputOptionPage.AddEx('Radio button 1', 0, True);
InputOptionPage.AddEx('Radio button 2', 0, True);
InputOptionPage.AddEx('Radio button 3', 0, True);
// initially select the first radio button
InputOptionPage.SelectedValueIndex := 0;
end;
function GetBinVer(Param: string): string;
begin
case InputOptionPage.SelectedValueIndex of
0: BinVer := '111111';
1: BinVer := '222222';
2: BinVer := '333333';
else RaiseException('Unexpected selection');
end;
end;
(not tested)
Though linking it to a code in CurUninstallStepChanged is more complicated, that happens in another (uninstaller) process. So you will have to store the selection/BinVer somewhere (e.g. Windows Registry), where you will load it from in the uninstaller. You might by able to use SetPreviousData/GetPreviousData.