Restricting instance to single instance?

[Tom Kreyche]

I have an 3rd party app with VBA embedded, and I want to use it simply as a
shell to call my C# application. This works fine using VBA's
CreateObject("Shell.Application") and ShellExecute.

However it opens a new instance of the C# program every time it is called,
which is undesirable. VBA is very limited in handling external calls, so is
there some way from within C# to only allow a single instance to be created.

I believe there is a way to do this with COM but ? .NET.

thanks, Tom

 

[Jon Skeet [C# MVP]]

I have an 3rd party app with VBA embedded, and I want to use it simply as a
shell to call my C# application. This works fine using VBA's
CreateObject("Shell.Application") and ShellExecute.

However it opens a new instance of the C# program every time it is called,
which is undesirable. VBA is very limited in handling external calls, so is
there some way from within C# to only allow a single instance to be created.

I believe there is a way to do this with COM but ? .NET.

See http://www.pobox.com/~skeet/csharp/faq/#one.application.instance

 

[Guest]

You will have to use Mutex to keep track of the application instance
...
using System.Threading
//include a private static memeber for your main clas

private static Mutex mtx = null
....
static void Main()

mtx = new Mutex(false, "MyMutex")

//Check whether any instance is already runnin
if(!mtx.WaitOne(0, true)

MessageBox.Show("goodbye")
return

Application.Run(new Form1())


----- Tom Kreyche wrote: ----

I have an 3rd party app with VBA embedded, and I want to use it simply as
shell to call my C# application. This works fine using VBA'
CreateObject("Shell.Application") and ShellExecute

However it opens a new instance of the C# program every time it is called
which is undesirable. VBA is very limited in handling external calls, so i
there some way from within C# to only allow a single instance to be created

I believe there is a way to do this with COM but ? .NET

thanks, To