Can I catch a missing dll error during application load in C#?

Question

Is it possible to catch the exception when a referenced .dll cannot be found?

For example, I have a C# project with a reference to a third-party dll; if that dll c

Answer 1

Extending Josh's answer.

Assemblies in .Net are loaded on demand by the CLR. Typically an assembly load won't be attempted until a method is JIT'd which uses a type from that assembly.

If you can't catch the assembly load failure with a try/catch block in the main method, it's likely beceause you're using a type from the assembly within the try/catch. So the exception occurs before the main method is actually run.

Try putting all of the code from the main method in a different function. Then call that function within the try/catch block and you should see the exception.

Answer 2

You can use AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);

  Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
    {
    }

To manually find the assembly if it can't find it automaticaly.

Answer 3

For a Form Application put the try/catch in Program.cs. (Expanding on JaredPat's answer).

Like this:

    [STAThread]
    static void Main()
    {
        try
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
            throw;
        }
    }

This will catch any missing DLL exceptions from your application. And they'll look similar to this:

Could not load file or assembly 'TheGreatestDLLEver.Tribute, Version=0.0.0.2, Culture=neutral, PublicKeyToken=jamtoastbutter' or one of its dependencies. The system cannot find the file specified.