End-user embedded programable VB inside C#

Question

How would it be possible to build a complete C# application with the feature of creating new functionalities thru new VB files. Those files shouldn't have to be compiled but interpreted in runtime.

I think of it as an embedded VB interpreter, but don't know how it can be accomplished. You could build a robust base application and then let your technicians adapt it to the particularities of each client (databases, tables, filters, network services,...)

A client of mine has a software with that open functionality but I ignore the details.

It also be great if python could be integrated!

Answer 1

Using VBCodeProvider you can compile VB.NET code at run-time.

The following example, compiles a piece of VB.NET code at run-time and run it:

private void button1_Click(object sender, EventArgs e)
{
    using (var vbc = new VBCodeProvider())
    {
        var parameters = new CompilerParameters(new[] {
        "mscorlib.dll",
        "System.Windows.Forms.dll",
        "System.dll",
        "System.Drawing.dll",
        "System.Core.dll",
        "Microsoft.VisualBasic.dll"});
        var results = vbc.CompileAssemblyFromSource(parameters,
        @"
        Imports System.Windows.Forms
        Imports System.Drawing
        Public Class Form1
            Inherits Form
            public Sub New () 
                Dim b as Button = new Button()
                b.Text = ""Button1""
                AddHandler b.Click, 
                    Sub (s,e)
                        MessageBox.Show(""Hello from runtime!"")
                    End Sub       
                Me.Controls.Add(b)
            End Sub
        End Class");

        //Check if compilation is successful, run the code
        if (!results.Errors.HasErrors)
        {
            var t = results.CompiledAssembly.GetType("Form1");
            Form f = (Form)Activator.CreateInstance(t);
            f.ShowDialog();
        }
        else
        {
            var errors = string.Join(Environment.NewLine,
                results.Errors.Cast<CompilerError>()
                .Select(x => x.ErrorText));
            MessageBox.Show(errors);
        }
    }
}