Suppressing Inno Setup task with a commandline parameter

Question

My goal is to create an installer that both can come up with a conditional parameter at startup but can have a checkable task too.

Via an optional parameter /NOAUTOSTART the installer should skip creating an entry in the Registry which lets the tool start at Windows login. Additionally this feature should be able to be toggled via a Task and lets the user decide, whether this feature should be enabled or not. Furthermore, if the parameter /NOAUTOSTART is passed while executing the installer, this task/window should be skipped anyways, therefore overruling this screen.

How is that possible?

I've been coming up with the following solution sofar:

[Tasks]
Name: autostartWhenChecked; Description: "Automatically start agent on login"

[Registry]
Root: HKLM; Subkey: "SOFTWARE\Microsoft\Windows\CurrentVersion\Run"; \
    ValueType: string; ValueName: "Updater Agent"; \
    ValueData: """{app}\Agent.exe"""; Flags: uninsdeletevalue; \
    Tasks: autostartWhenChecked;

This successfully handles the checkbox in my installer.

But in combination with the following, retrieving the startup parameter (thanks to this answer: Passing conditional parameter in Inno Setup):

[Code]
function CmdLineParamExists(const Value: string): Boolean;
var
  I: Integer;  
begin
  Result := False;
  for I := 1 to ParamCount do
    if CompareText(ParamStr(I), Value) = 0 then
    begin
      Result := True;
      Exit;
    end;
end;

function ShouldEnableAutostart: Boolean;
begin
    if CmdLineParamExists('/NOAUTOSTART') then
        begin
            Checkbox :=
                WizardForm.TasksList.Items.IndexOf(
                    'Automatically start agent on login');
            WizardForm.TasksList.CheckItem(Checkbox, coUncheck);
            Result := False;
        end
    else
        Result := True;
end;

I can't combine those two possibilities. Furthermore I'm struggling on how to get the index of the task, the code above always returns an index out of bounds (-1). Seems like the description text of the task can't be found anyhow.

Answer 1

Just hide the task, using the Check parameter referring to your CmdLineParamExists function, if it detects that the command-line parameter is specified.

[Tasks]
Name: autostartWhenChecked; Description: "Automatically start agent on login"; \
   GroupDescription: "{cm:AdditionalIcons}"; \
   Check: not CmdLineParamExists('/NOAUTOSTART')