Inno Setup function not called

Question

I would like the [InstallDelete] section to call a custom function that will check if an older version is installed (in which case certain files need to be deleted prior installation of the new version).

Extract from my Inno Setup script. First the function that returns True if an older version is installed.

[Code]
function deleteExistingHhd: Boolean;
var Version: String;
begin
  MsgBox('Checking for key:'+'Software\Microsoft\Windows\CurrentVersion\Uninstall\'+ExpandConstant('AppId')+'_is1', mbInformation, MB_OK);

  if RegValueExists(HKEY_LOCAL_MACHINE,'Software\Microsoft\Windows\CurrentVersion\Uninstall\'+ExpandConstant('AppId')+'_is1', 'DisplayVersion') then
    begin
      RegQueryStringValue(HKEY_LOCAL_MACHINE,'Software\Microsoft\Windows\CurrentVersion\Uninstall\'+ExpandConstant('AppId')+'_is1', 'DisplayVersion', Version);
      MsgBox('Existing version:'+Version+'  New version:'+ExpandConstant('AppVersion'), mbInformation, MB_OK);
      if (Version < '1.013') then
        begin
          Result := True;
        end
      else
        begin
          Result := False;
        end
    end
  else
    begin
      Result := False;
    end
end;

Then the section that should call this function:

[InstallDelete]
Type: files; Name: {userappdata}\xxx\*.hhd; Check:deleteExistingHhd;

Unfortunately the generated setup seems to never call the custom function (when installing my program with this setup I never get the MsgBox located in the custom function and the files are not deleted).

Is it possible that my function has some errors that are not indicated when Inno Setup compiles? If so, where could I find them?

Any help / hint would be very much appreciated; thanks!

I thing you error is in ExpandConstant('AppId') and ExpandConstant('AppVersion') — IZB
Thanks but this is not the error: I need to find registry based on AppId (GUID). Beyond finding the specific error here, the more general question is: where can I find an error log that would indicate where the error is coming from? — Tom
I mean you code not work because ExpandConstant('AppId') it's not give you AppId (GUID). if you want to do it you can use #define AppId SetupSetting('AppId') and called it with ExpandConstant('{#AppId}') — IZB

papo papo · Accepted Answer · 2015-09-16T20:26:31

If the MsgBox is never called, there is something else wrong.
I created a new project, pasted your lines as-is and the first msgbox pops-up.

Maybe just start a new, and keep adding parts from your old setup script until you'll find what is stopping the function from executing.

Did you know you can step through the code using F7 and/or breakpoints F5? That should help you locate the problem, It should go: [InstallDelete] -> [Dirs] -> [Files]

@IZB is right, ExpandConstant('AppId') will be resolved as AppId and not the actual ID. Check the output from the debugging section I added the your script below. Watch the "Debug output" on bottom of Inno Seput Compiler while stepping through the code.

AND, You also need the ExpandConstant :) because otherwise you'll get the leading '{' doubled. It should be doubled in [Setup] section to escape the bracket character. The pre-compiler will pass the escape leading bracket too, using #SetupSetting("AppId") . ExpandConstant will not actually Expand any constant here, but will remove this doubled bractet.

Here is paste of complete working iss file:

#define MyAppName "My Program"
#define MyAppVersion "1.5"
#define MyAppPublisher "My Company, Inc."
#define MyAppURL "http://www.example.com/"
#define MyAppExeName "MyProg.exe"

[Setup]
AppId={{CB77C990-DECF-4697-B377-8F76799CC6B7}
AppName={#MyAppName}
AppVersion={#MyAppVersion}
;AppVerName={#MyAppName} {#MyAppVersion}
AppPublisher={#MyAppPublisher}
AppPublisherURL={#MyAppURL}
AppSupportURL={#MyAppURL}
AppUpdatesURL={#MyAppURL}
DefaultDirName={pf}\{#MyAppName}
DefaultGroupName={#MyAppName}
OutputBaseFilename=setup
Compression=lzma
SolidCompression=yes

[Code]
function deleteExistingHhd: Boolean;
var Version: String;
begin

  // Debugging
  // {#SetupSetting("AppId")} is short from {#emit SetupSetting("AppId")}
  Log('Note the double bracket: {#SetupSetting("AppId")}');
  Log('Now it''s fine: ' + ExpandConstant('{# SetupSetting("AppId")}'));
  Log(' This won''t expand: ' + ExpandConstant('AppId'));

  if RegValueExists(HKEY_LOCAL_MACHINE,ExpandConstant('Software\Microsoft\Windows\CurrentVersion\Uninstall\{#SetupSetting("AppId")}_is1'), 'DisplayVersion') then
    begin
      RegQueryStringValue(HKEY_LOCAL_MACHINE,ExpandConstant('Software\Microsoft\Windows\CurrentVersion\Uninstall\{#SetupSetting("AppId")}_is1'), 'DisplayVersion', Version);
      MsgBox('Existing version:' + Version + '  New version:{#SetupSetting("AppVersion")}', mbInformation, MB_OK);
      if (Version < '1.013') then Result := True
      else Result := False;
    end
  else Result := False;
end;

[InstallDelete]
Type: files; Name: {userappdata}\xxx\*.hhd; Check: deleteExistingHhd

Inno Setup function not called

2 Answers