Inno Setup: How to change Messages at runtime? - installation

Question

I need to change Messages at runtime. I have a AfterInstall procedure that checks to see if a bat file was successful. If it is not, I want to change the value of ExitSetupMessage just before calling WizardForm.Close. I was hoping to do something like this english.ExitSetupMessage := 'THIS IS THE PART THAT DOES NOT WORK';. Code examples would be appreciated. Thank you.
[Languages]
Name: english; MessagesFile: compiler:Default.isl
[Files]
Source: {src}\test.bat; DestDir: {tmp}; AfterInstall: ValidateInstall
[Code]
procedure ValidateInstall();
var
ResultCode : Integer;
begin
if not Exec(ExpandConstant('{tmp}\test.bat'), '', '', SW_HIDE, ewWaitUntilTerminated, ResultCode) then
begin
english.ExitSetupMessage := 'THIS IS THE PART THAT DOES NOT WORK';
WizardForm.Close;
end;
end;

Answer 1

I don't know of a way to change the messages at runtime.
However in the case you posted I know of a workaround. You would set your CustomState before calling WizardForm.Close
var
CustomState : Boolean;
procedure CancelButtonClick(CurPageID: Integer; var Cancel, Confirm: Boolean);
var
Msg : String;
Res : Integer;
begin
Confirm := False; // Don't show the default dialog.
// Chose which message the custom or default message.
if CustomState then
Msg := 'My Custom Close Message'
else
Msg := SetupMessage(msgExitSetupMessage);
//as the Question
Res := MsgBox(Msg, mbConfirmation,MB_OKCANCEL);
// If they press OK then Cancel the install
Cancel := (Res = IDOK);
end;
The side effect is you lose the Exit Setup? title of the dialog box.
You can use function ExitSetupMsgBox: Boolean; when you don't want to change the message
to keep the title around.

Answer 2

According to http://www.jrsoftware.org/ishelp/index.php?topic=scriptclasses
it should be
WizardForm.FinishedLabel.Caption := 'Desired text goes here';