Sunday, May 22, 2011

Create Shortcut in C#

Last week I was working on a case to provide support for an application users. The application has two executables: one is app's main exe like app.exe and another one is for app's update like appUpdate.exe. For this update, we need to add a shortcut on clients machine desktop pointed to appUpdate.exe.

Like a typical shortcut, the one I need to put on client PCs has several settings: target, start in, run mode, icon and comments.

I tried to create a shortcut on my box first. Aftert that, I tried to copy this shortcut file (lnk) to a remote PC. It did not work. It seems that the lnk file some information are embedded in the file. When it is not in the machine where it was created. The machine name appears in the target.

I need a way to create a shortcut on fly. That's why I went to .net to create a simple console app do the job. This time SO helped me with an excellent open source library from a QA: ShellLink.cs. Within the source codes, there are actually two files I need: ShellLink.cs and FileIcon.cs. The library contains a wrapper class for Windows APIs. It is very straight forward.

The only change I made is to add a class level flag for any changes in shortcut properties. If any setter changes a value, this flag is true. Then I'll only save chances for the shortcut if any of properties are changed.

public class ShellLink : IDisposable {
private bool mChanged = false;
public string Target {
get { .... }
set { if (!value.Equals(Target)) {
mChanged = true;