先來張運行時截圖：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Microsoft.CSharp;
using System.CodeDom.Compiler;
using System.Reflection;

namespace CSharpDynamicCode
{
    
 
public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnRun_Click(object sender, EventArgs e)
        {
            run();
        }

        void run()
        {
            CSharpCodeProvider objCSharpCodePrivoder 
 
= new CSharpCodeProvider();
            ICodeCompiler objICodeCompiler = objCSharpCodePrivoder.CreateCompiler();

            CompilerParameters objCompilerParameters = new CompilerParameters();

            //添加需要引用的dll
            objCompilerParameters.ReferencedAssemblies.Add("System.dll");
            objCompilerParameters.ReferencedAssemblies.Add(
 
"System.Windows.Forms.dll");

            //是否生成可執行文件
            objCompilerParameters.GenerateExecutable = false;

            //是否生成在內存中
            objCompilerParameters.GenerateInMemory = true;

            //編譯代碼
            CompilerResults cr = objICodeCompiler.CompileAssemblyFromSource(objCompilerParameters, txtCode.Text);

            if (cr.Errors.HasErrors)
            {
                var msg = string.Join(Environment.NewLine, cr.Errors.Cast<CompilerError>().Select(err => err.ErrorText));
                MessageBox.Show(msg, "編譯錯誤");
            }
            else
            {
                Assembly objAssembly = cr.CompiledAssembly;
                object objHelloWorld = objAssembly.CreateInstance("Test");
                MethodInfo objMI = objHelloWorld.GetType().GetMethod("Hello");
                objMI.Invoke(objHelloWorld, null);
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }
    }
}

https://www.cnblogs.com/nanfei/p/6046128.html

/// <summary>
        /// 動態編譯並執行代碼
        /// </summary>
        /// <param name="code">代碼</param>
        /// <param name="newPath">輸出dll的路徑</param>
        /// <returns>返回輸出內容</returns>
        private CompilerResults debugRun(string[] code, string newPath)
        {
            CSharpCodeProvider complier = new CSharpCodeProvider();
            //設置編譯參數
            CompilerParameters paras = new CompilerParameters();
            //引入第三方dll
            paras.ReferencedAssemblies.Add(@"System.dll");
            paras.ReferencedAssemblies.Add(@"System.configuration.dll");
            paras.ReferencedAssemblies.Add(@"System.Data.dll");
            paras.ReferencedAssemblies.Add(@"System.Management.dll");
            paras.ReferencedAssemblies.Add(@"System.Web.dll");
            paras.ReferencedAssemblies.Add(@"System.Xml.dll");
            paras.ReferencedAssemblies.Add(@"F:\AuthorizationService\Lib\Newtonsoft.Json\Net20\Newtonsoft.Json.dll");
            //引入自定義dll
            //paras.ReferencedAssemblies.Add(@"D:\自定義方法\自定義方法\bin\LogHelper.dll");
            //是否內存中生成輸出
            paras.GenerateInMemory = false;
            //是否生成可執行文件
            paras.GenerateExecutable = false;
            paras.OutputAssembly = newPath;

            //編譯代碼
            CompilerResults result = complier.CompileAssemblyFromSource(paras, code);

            return result;
        }

http://www.cnblogs.com/feigao/p/6197167.html

C#動態編譯並執行代碼