Inno Setup GetExceptionMessage returns empty message - exception

Question

in Inno Setup script GetExceptionMessage returns empty message (it contains only colon ":" sign). The last version of Inno Setup (5.4.2) is used.
try
Log('Create IISNamespace');
// Create IIS namespace object
if Length(virtualDirectoryName) > 0 then
begin
IIS := CreateOleObject('IISNamespace');
Log('Get IIsWebService');
WebSite := IIS.GetObject('IIsWebService', IISServerName + '/w3svc');
Log('Get IIsWebServer');
WebServer := WebSite.GetObject('IIsWebServer', IISServerNumber);
Log('Get IIsWebVirtualDir');
WebRoot := WebServer.GetObject('IIsWebVirtualDir', 'Root');
Log('Delete IIsWebVirtualDir');
WebRoot.Delete('IIsWebVirtualDir', virtualDirectoryName);
WebRoot.SetInfo();
end;
except
MsgBox(ExpandConstant('{cm:IISException,'+ GetExceptionMessage +'}'),
mbInformation, mb_Ok);
Log('Uninstall IIS 6 exception: ' + GetExceptionMessage);
end;
The exception occurs during deleting IIsWebVirtualDir.
Is there any way to get exception type or real exception message?
Thanks, Denis.

Answer 1

I just wrote the following example to see if either GetExceptionMessage or ShowExceptionMessage are broken. I used both Inno setup 5.4.2 Unicode and Ansi versions.
[Setup]
AppName=Test
AppVersion=1.5
DefaultDirName={pf}\test
[Code]
function InitializeSetup(): Boolean;
var
I: Integer;
begin
try
I := I div 0; // Raise an exception
except
MsgBox(GetExceptionMessage,
mbError, MB_OK);
ShowExceptionMessage;
end;
result := false;
end;
I also ran CodeAutomation.iss that ships and it worked as expected. Which is contrary to the comment made by Alex K. that it may be broken.
Now that I know that the routines should work, I took your code and made the following setup test Script and ran it and it raised an exception on not finding the ISSNamespace as I don't have it installed.
[Setup]
AppName=Test
AppVersion=1.5
DefaultDirName={pf}\test
[CustomMessages]
IISException =ISS Exception " %1 " occured.
[Code]
const
IISServerName = 'localhost';
IISServerNumber = '1';
IISURL = 'http://127.0.0.1';
function InitializeSetup(): Boolean;
var
IIS, WebSite, WebServer, WebRoot, VDir: Variant;
virtualDirectoryName : String;
begin
virtualDirectoryName := 'test';
try
Log('Create IISNamespace');
// Create IIS namespace object
if Length(virtualDirectoryName) > 0 then
begin
IIS := CreateOleObject('IISNamespace');
Log('Get IIsWebService');
WebSite := IIS.GetObject('IIsWebService', IISServerName + '/w3svc');
Log('Get IIsWebServer');
WebServer := WebSite.GetObject('IIsWebServer', IISServerNumber);
Log('Get IIsWebVirtualDir');
WebRoot := WebServer.GetObject('IIsWebVirtualDir', 'Root');
Log('Delete IIsWebVirtualDir');
WebRoot.Delete('IIsWebVirtualDir', virtualDirectoryName);
WebRoot.SetInfo();
end;
except
MsgBox(ExpandConstant('{cm:IISException,'+ GetExceptionMessage +'}'),
mbInformation, mb_Ok);
Log('Uninstall IIS 6 exception: ' + GetExceptionMessage);
end;
end;
But I made a fatal flaw during the construction of this script that could be your problem.
Check your [CustomMesssages] section make sure you have %1 in the message. Otherwise nothing is returned.