Creating CobView plugins

To CobViews page

 Please, download this DEMO plug-in in Delphi

If you are a developer, you may want to create your own plug-in. If you create a cool plug-in and want to publish it, please, send it to me to and I will put it on the program's site.

I am NOT responsible for any 3rd parts plug-in. You, as the plug-in author are the responsible for your plug-in functionality and support.

How does it work?

CobView is a shell extension in the form of a context menu that shows when the user right clicks on any file or folder on Windows Explorer. When the user clicks on CobView, the following actions happen:  

  • The program CobView.exe is loaded.  
  • This program search the registry on the key HKEY_LOCAL_MACHINE\SOFTWARE\Cobian\CobView\Ext where the associations are stored.  
  • If the extension of the selected file is found there, the associated plugin is called and the file name is passed to it.  
  • If the extension is NOT found on the registry, the CobGeneral.dll plugin is called then.


As a plug-in developer you can create your plug-ins in any language you want.

A plug-in MUST have 2 exported procedures with a fixed format.

All other procedures and functions are free. You can download a plug-in example here.

 The two obligatory procedures that must be present on a plug-in are:

procedure RegisterExt;stdcall;

procedure ShowInfo(FileName:PChar);stdcall;

The first procedure is used to register the extensions by the program CobReg.exe. An example in Delphi of what this procedure may do is:

procedure RegisterExt;stdcall;
DllName:array[0..MAX_PATH] of char;  
//Register the extensions that the DLL handles
      if Reg.OpenKey ('SoftWare\Cobian\CobView\Ext\',true) then

In this example, the program will register the extensions ex1 and ex2 to be open with your plug-in.

 The second procedure will receive the file name as a PChar and it is up to you what to do with this file name. I recommend you to download the sample program from my site.

Some guidelines:

  • Your plug-in may include a readme file with your Copyright and other legal information. (for example that YOU are the responsible for your plug-in as the author)
  • If you store some configuration keys on the registry, please use the key HKEY_CURRENT_USER\Software\Cobian\CobView\Plugins\YourPlugin where YourPlugin is your plug-in name. See the Delphi example on my site.
  • You can provide your own about box, but you can use my standard box for plug-ins by passing to it your own information. See again the Delphi example.

Happy programming!