How to detect if another assembly is available to my application or not.

Question

I have a command line winforms executable that calls into a Windows winforms application.

Occassionally Ops forget to include the windows exe with the command line exe when deploying the application, leading to an error.

How do I gracefully handle that and show a nice error instead of:

Unhandled Exception: System.IO.FileNotFoundException: Could not load file or ass embly 'MyappFoo, Version=5.1.4303.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified. File name: 'MyAppFoo, Version=5.1.4303.0, Culture=neutral, PublicKeyToken=null' at AppFoo.Program.Main(String[] args)

WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\M icrosoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure lo gging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fus ion!EnableLog].

Edit:

To clarify a bit, how do I intercept the FileNotFoundExcception, when

static int Main(string[] args)
{
   try
   {
      Console.WriteLine"MyPhooApp Command Line (c) PhooSoft 2008");
   }
   catch (System.IO.FileNotFoundException fe)
   {
      Console.WriteLine("Unable to find foo.exe");
      return -1;
   }
}

doesnt writeln either.

Answer 1

You can use the Reflection-Only loading capability introduced in .NET 2.0. This allows you to load an assembly for inspection without actually loading it into the appdomain.

Assembly.ReflectionOnlyLoad

Assembly.ReflectionOnlyLoadFrom

Answer 2

Could you not simply look for the file with FileInfo.Exists?