Associate File Extension with Shell OPEN command and Application

Introduction

This source contains a class CGCFileTypeAccess that can associate a file extension with a program.

The association allows a new instance of the program to be activated when the icon is clicked upon in the Windows Explorer window. The full file path to the file will be sent to the program on the command line.

The Open command also appears on the shell context menu for the file type. Selection of the open command from the context menu sends the file on the command line to a new instance of the program.

An example of associating a file extension using the class would be done as follows, and can be found in the InitInstance of the demo program:

CGCFileTypeAccess TheFTA;

// get full file path to program executable file

TCHAR	szProgPath[MAX_PATH * 2];
::GetModuleFileName(NULL, szProgPath, sizeof(szProgPath)/sizeof(TCHAR));

CString csTempText;

TheFTA.SetExtension("CGFILETYPETEST");

// just pass file path in quotes on command line

csTempText  = szProgPath;
csTempText += " \"%1\"";
TheFTA.SetShellOpenCommand(csTempText);
TheFTA.SetDocumentShellOpenCommand(csTempText);

TheFTA.SetDocumentClassName("CGFileType.Document");

// use first icon in program

csTempText  = szProgPath;
csTempText += ",0";
TheFTA.SetDocumentDefaultIcon(csTempText);

// set the necessary registry entries	

TheFTA.RegSetAllInfo();

The relevant registry entries are all under HKEY_CLASSES_ROOT. The two primary root keys are .'FileExtension' and 'Document Class Name'. Keys and values underneath these two primary keys control the file association and the shell open command.

The demo program will execute the file association code listed above. After it has been run at least once, each time you 'open' one of the associated file types, the program will display the file path from the command line in a message box.