CodeDom : compile partial class

I'm attempting to compile code in a text file to change a value in a TextBox on the main form of a WinForms application. Ie. add another partial class with method to the calling form. The form has one button (button1) and one TextBox (textBox1). The code in the text file is: this.textBox1.Text = "Hello World!!"; And the code: ``` namespace WinFormCodeCompile { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { // Load code from file StreamReader sReader = new StreamReader(@"Code.txt"); string input = sReader.ReadToEnd(); sReader.Close(); // Code literal string code = @"using System; using System.Windows.Forms; namespace WinFormCodeCompile { public partial class Form1 : Form { public void UpdateText() {" + input + @" } } }"; // Compile code CSharpCodeProvider cProv = new CSharpCodeProvider(); CompilerParameters cParams = new CompilerParameters(); cParams.ReferencedAssemblies.Add("mscorlib.dll"); cParams.ReferencedAssemblies.Add("System.dll"); cParams.ReferencedAssemblies.Add("System.Windows.Forms.dll"); cParams.GenerateExecutable = false; cParams.GenerateInMemory = true; CompilerResults cResults = cProv.CompileAssemblyFromSource(cParams, code); // Check for errors if (cResults.Errors.Count != 0) { foreach (var er in cResults.Errors) { MessageBox.Show(er.ToString()); } } else { // Attempt to execute method. object obj = cResults.CompiledAssembly.CreateInstance("WinFormCodeCompile.Form1"); Type t = obj.GetType(); t.InvokeMember("UpdateText", BindingFlags.InvokeMethod, null, obj, null); } } } } ``` When I compile the code, the CompilerResults returns an error that says WinFormCodeCompile.Form1 does not contain a definition for textBox1. Is there a way to dynamically create another partial class file to the calling assembly and execute that code? I assume I'm missing something really simple here.