Dynamic class creation in C#

Question

Is it possible in runtime to create a class from DataTable where ColumnName will be dynamic-class properties?

Answer 1

I am going to be looking into the ExpandoObject that was mentioned (I voted for that solution by the way as it seems easier) but yes, it is possible. I'm building a class in one of my projects where a third party utility requires a CSV line to be defined as a class.

You can build the code (I included \r\n so that I could read the resultant code):

        string code = "using FileHelpers;\r\n\r\n";

        code += "[DelimitedRecord(\"" + delimiter + "\")]\r\n";
        code += "public class CustomCSVInputFile ";
        code += "{ \r\n";

        foreach (string column in columnList)
        {
          code += "   public string " + column.Replace(" ", "") + ";\r\n";
        }
        code += "}\r\n";

        CompilerResults compilerResults = CompileScript(code);

...

    public static CompilerResults CompileScript(string source)
    {
        CompilerParameters parms = new CompilerParameters();
        FileHelperEngine engine;

        parms.GenerateExecutable = false;
        parms.GenerateInMemory = true;
        parms.IncludeDebugInformation = false;

        string path = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase).Replace("file:\\", "").Trim();

        parms.ReferencedAssemblies.Add(Path.Combine(path, "FileHelpers.dll"));

        CodeDomProvider compiler = CSharpCodeProvider.CreateProvider("CSharp");

        return compiler.CompileAssemblyFromSource(parms, source);
    } 

... Like I mentioned, If I had to do it over again I would investigate the ExpandoObject but it is definitely possible to create a class from a DataTable. You would need to interrogate the column names to build your fields; my example had the list of column names provided from a "," delimited string.

My example is from a very specific use case but it should be enough to get you going should the ExpandoObject not work for you.