Chm file freeze the application when Url or Print buttons were clicked

Question

When I open help file from my Windows Forms application I'm using this code.

    public static void ShowHelp(string constant)
    {
        Help.ShowHelp(dummyFormForHelp.Value, CHMFile, HelpNavigator.Topic, constant);
    }

It works fine except when I click on GO>URL... or Print button in the help file. [

I get no messages and the app and chm file don't response at all. And I need go to task manager and kill the process. I have no idea what it is.

I tried to open the same file using the same code from the simple Windows Form application with only one form and everything was perfect. So I think something wrong in my application.

What can cause such issue? It's a big enterprise application with a lot of screens.

Answer 1

First of all question is not quite clear described:

• It should be mentioned that chm file is generated by NuHelp (it was temporary solution but we all know temporary is always permanent, huh?) )
• dummyFormForHelp.Value says nothing here, it is just lazy initialized instance of form to prevent topmost position of help window and allow to switch between application and help

dummyFormForHelp.Value means:

private static readonly Lazy<Form> dummyFormForHelp = new Lazy<Form>(() =>
{
    var form = new Form();
    form.CreateControl();
    return form;
});

Back to original issues with WinForms<>CHM Help:

• issues are appeared only if help is opened by application, if help is opened directly - no issues at all
• endless loop is caught in 100% when navigating to URL, Print or typing any world in Search tab

Research shows that your issue with frozen application and opened chm is not unique:

• Bug in some versions of Windows
• Issues with CHM generated by RoboHelp
• Topic on connect Help.ShowHelp hangs in endless loop on Windows 10 and astonishing answer: Unfortunately, this is an issue with the Windows Help System, not Windows Forms. Connect feedback is not currently being accepted by the team that owns the Help system, so we cannot route this as a connect issue. We appreciate your report.
• Example of stack with hang here

Solution

Ways of resolving issue:

• Try the last version of NuHelp
• Try different converters and check if it can help
• Do not use any converter and generate help file on your own
• Start help as different process

Start help as different process:

hh is added to windows path, so such commands can be executed easily:

hh "help.chm::/topic.html"

hh "help.chm::/topic.html#subtopic"

hh -mapid 12345 help.chm

Drawback of workaround: each call of help from application will open new instance of help.

EDIT: 28/08/2017

For future readers:

• recompilation by different commonly used converters did not help
• help was recreated with Help&Manual,
• Index was returned and keywords were configured properly, Search was returned
• calling of hh was used

Now help works as expected.