[2.0] Bring another, running Application to Focus

[Kasracer]

Is there a way to bring in another, running application into Focus entirely in .Net (so I can avoid API calls)?

I'm basically trying to make it so only 1 instance of my app is shown and if a user tries to run another instance, it brings the already running versions to the front.

[jmcilhinney]

The only way that I'm aware of that doesn't use APIs is the VB.NET AppActivate function, but it won't restore a minimised window. VB 2005 has single-instance functionality built in. I don't know of one but there may be a way to leverage that functionality from a C# app. I've seen articles about using the VB My namespace in C# so it might be an extension of that.

[Kasracer]

I submitted an article in the codebank about using a Mutex class to create a single-instance and that works great but I don't see anyway of leveraging that to bring the first instance into focus.

Not sure how to use any of the VB specific methods to help in this situation.

I would use an API to do this but I'd like to stay away from it so my app will continue to run under the Mono framework (so I can run it on linux).

[jmcilhinney]

I'd guess that VB-specific features like Runtime functions and My would be low on the list of priorities for Mono as most people developing for Mono would be using C#. I'm not aware of any "pure .NET" method of doing what you want, outside of the in-built VB 2005 support that may never see the light of day in Mono. I suppose that you could set up some form of IPC between instances of your app, so the new instance can speak directly to the existing instance.

[sunburnt]

You can use the System.Diagnostics.Process.GetProcessesByName() to get a Process object that represents your other process, and then perhaps write a message to it on it's StandardInput. In your code, you could have a thread polling on the standard input, and if you receive a message, bring the application to the front.

Probably not the best way to do it, but probably pretty portable.

Edit:
If you add a reference to Microsoft.VisualBasic.dll, you can do the following:

I couldn't test this under mono since apparently my mono install seems to have been borked and can't load libgdiplus, even though it's specified in LD_LIBRARY_PATH.

Process pThis = Process.GetCurrentProcess();
Process[] pMatches = Process.GetProcessesByName(pThis.ProcessName);
if (pMatches.Length == 2)
{
     Process pOther = pMatches[0];
     if (pOther.Id == pThis.Id)
          pOther = pMatches[1];
     Microsoft.VisualBasic.Interaction.AppActivate(pOther.Id);
     return;
               
}

[Kasracer]

I can't use GetProcessesByName() as it is not reliable. If my app's executable is "MyApp.exe" and company Y already makes a product with its executable name as "MyApp.exe", then I may get their process and not mine.

This was one of the reasons I'm using a Mutex to ensure only 1 instance of my app is active at any given time.

I'm going to look into using IPC for this.

[dee-u]

How about this?

[Kasracer]

How about this?

I already said I'm trying to stay away from using the Win32 API.