Open CHM (help file) in C#

Question

I'm trying to open help file (chm extension) in C#.

File.Open(@"//help.chm",FileMode.Open, FileAccess.Read, FileShare.Read);

and

FileStream fileStream = new FileStream(@"c:\help.chm", FileMode.Open);

doesn't work :(

Answer 1

        string helpFileName = @"c:\help.chm";
        if (System.IO.File.Exists(helpFileName))
        {
            Help.ShowHelp(this, helpFileName );                
        }

if this is not work try

        if (System.IO.File.Exists(helpFileName))
        {
            System.Diagnostics.Process.Start(helpFileName);              
        }

Answer 2

You can use -

System.Windows.Forms.Help.ShowHelp(Control, String)

So assuming you are in a Form/Control

Help.ShowHelp(this, "file://c:\\helpfiles\\help.chm");

ShowHelp method also provides overloads to go to specific topic and help page located inside the compiled HTML help file.

Read System.Windows.Forms.Help.ShowHelp on MSDN

Decompiling a CHM file

Is as easy as executing below command in the command prompt.

hh.exe -decompile <target-folder-for-decompiled-content> <source-chm-file>

For Example:

hh.exe -decompile C:\foo\helpchmextracted help.chm

After executing the above command you should find the decompiled content in the C:\foo\helpchmextracted folder.

Answer 3

Adding my comments to an answer as per request:

It seems that the file name in the first statement is not correct however the second one should work unless the file is locked, not exists or you don't have permissions to access the file. If you want to ShellExecute the file then you should use System.Diagnostics.Process class, but if you want to extract the contents of the CHM, since is compiled and formatted, it can't be read like plain text files. Take a look at these links:

Decompiling CHM (help) files with C#

CHM Help File Extractor