Imports System.CodeDom.Compiler
Imports System.Reflection

Public Class FormMain

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' 编译参数
        Dim cpars As New CompilerParameters

        ' 编译参数，如 /optimize /removeintchecks 等
        cpars.CompilerOptions = "/optimize "

        cpars.GenerateInMemory = True '在内存中编译而不输出文件
        cpars.GenerateExecutable = False '并不输出执行文件
        cpars.IncludeDebugInformation = False '不需要调试信息

        ' 导入类库（根据自己代码的需要导入）
        cpars.ReferencedAssemblies.Add("mscorlib.dll")
        cpars.ReferencedAssemblies.Add("System.dll")
        cpars.ReferencedAssemblies.Add("System.Data.dll")
        cpars.ReferencedAssemblies.Add("System.Deployment.dll")
        cpars.ReferencedAssemblies.Add("System.Drawing.dll")
        cpars.ReferencedAssemblies.Add("System.Windows.Forms.dll")
        cpars.ReferencedAssemblies.Add("System.Xml.dll")
        cpars.ReferencedAssemblies.Add("Microsoft.VisualBasic.dll")

        ' 编译参数，为导入的类库设置全局引用（否则必须使用完整的命名空间名称才能正确调用函数）
        cpars.CompilerOptions &= " /imports:" & _
         "Microsoft.VisualBasic," & _
         "System," & _
         "System.Collections," & _
         "System.Collections.Generic," & _
         "System.Drawing," & _
         "System.Windows.Forms"

        ' 设置编译器
        Dim vbc As New VBCodeProvider
        'Dim vbc = CodeDomProvider.CreateProvider("VisualBasic") '等效方法

        ' 一个简单的模板类
        Dim codex As String = _
         "Public Class CompClass" & vbCrLf & _
         "    Shared Function RunCode() As Object" & vbCrLf & _
         "        '$" & vbCrLf & _
         "    End Function" & vbCrLf & _
         "End Class"

        ' 替换代码到模板类中
        Dim code As String = codex.Replace("'$", TextBox1.Text)


        ' 编译并返回
        Dim resut As CompilerResults = vbc.CompileAssemblyFromSource(cpars, code)

        ' 如果发生了错误
        If resut.Errors.Count > 0 Then
            MsgBox(resut.Errors(0).ToString)
            Return
        End If


        ' 尝试调用代码
        Dim asm As Assembly = resut.CompiledAssembly '获取程序集

        ' 获取我们编写的静态方法
        Dim mi As MethodInfo = asm.GetType("CompClass").GetMethod("RunCode")

        ' 执行代码，并获取返回值
        Dim ret As Object = mi.Invoke(Nothing, Nothing)

        ' 对返回值进行处理
        If ret IsNot Nothing Then
            MsgBox(ret.ToString)
        End If

    End Sub

End Class

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using System.Reflection;
using System.CodeDom.Compiler;

namespace WindowsFormsApplication1
{
    public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
        }

        private void Button1_Click(object sender, EventArgs e)
        {
            // 编译参数
            var cpars = new CompilerParameters();
            cpars.CompilerOptions = "/optimize ";
            cpars.GenerateInMemory = true;
            cpars.GenerateExecutable = false;
            cpars.IncludeDebugInformation = false;

            // 导入类库（根据自己代码的需要导入）
            cpars.ReferencedAssemblies.Add("mscorlib.dll");
            cpars.ReferencedAssemblies.Add("System.dll");
            cpars.ReferencedAssemblies.Add("System.Data.dll");
            cpars.ReferencedAssemblies.Add("System.Deployment.dll");
            cpars.ReferencedAssemblies.Add("System.Drawing.dll");
            cpars.ReferencedAssemblies.Add("System.Windows.Forms.dll");
            cpars.ReferencedAssemblies.Add("System.Xml.dll");

            // 编译器实例
            var csc = new Microsoft.CSharp.CSharpCodeProvider();
            //var csc = CodeDomProvider.CreateProvider("CSharp");

            // 一个简单的模板类
            // 因为C#的编译器无法设置全局命名空间，所以需要在代码中导入命名空间
            var codex = @"
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
class CompClass{
    static public object RunCode(){
        //$
        return null;
    }
}
";

            // 替换代码到模板类中
            var code = codex.Replace("//$", TextBox1.Text);

            // 编译并返回
            var resut = csc.CompileAssemblyFromSource(cpars, code);

            // 错误警告
            if (resut.Errors.Count > 0) {
                MessageBox.Show(resut.Errors[0].ToString());
                return;
            }

            // 调用代码
            var asm = resut.CompiledAssembly;
            var mi = asm.GetType("CompClass").GetMethod("RunCode");

            object ret = mi.Invoke(null, null);
            if (ret != null) {
                MessageBox.Show(ret.ToString());
            }
        }
    }
}