从Nuget安装

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;

 

如果语法有错误,就会在下面的textbox显示编译错误

/// <summary>
        /// 多运行几次,就过100M内存了.不定期GC后也要占用50M
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnRun_Click(object sender, EventArgs e)
        {
            txtErr.Text = "";
            var text = txtScript.Text;
            var tree = SyntaxFactory.ParseSyntaxTree(text);

            var systemReference = MetadataReference.CreateFromFile(typeof(object).Assembly.Location);

            var compilation = CSharpCompilation.Create("calc.dll")
                .AddSyntaxTrees(tree)
                .AddReferences(systemReference)
                .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));

            Assembly compiledAssembly;
            //string outputPath = System.Windows.Forms.Application.StartupPath + "\\PlugIn\\" + "calc.dll";
            //calc.dll保存在内存,没保存在文件
            using (var stream = new MemoryStream())
            {
                var compileResult = compilation.Emit(stream);
                //var compileResult = compilation.Emit(outputPath);//假如保存到c盘,需要权限
                //用文件的话,再Emit的时候,会出现calc.dll”正由另一进程使用，因此该进程无法访问此文件。”

                if (!compileResult.Success)
                {
                    foreach (var item in compilation.GetDiagnostics())
                    {
                        txtErr.Text+= item.GetMessage() + Environment.NewLine;
                    }
                    MessageBox.Show("编译失败");
                    return;
                }
               
                compiledAssembly = Assembly.Load(stream.GetBuffer());
                //compiledAssembly = Assembly.LoadFile(outputPath); 
            }

            try
            {
                var calculatorClass = compiledAssembly.GetType("Calculator");
                if(calculatorClass!=null)
                {
                    var evaluateMethod = calculatorClass.GetMethod("Evaluate");
                    var result = evaluateMethod.Invoke(null, null).ToString();
                    Console.WriteLine(result);
                    MessageBox.Show(result);
                }
            }
               
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);

            }

        }
        //占用30M内存
        private void btnSnippet_Click(object sender, EventArgs e)
        {
            try
            {
                var scriptState = CSharpScript.RunAsync<int>("if(DateTime.Now.Hour<12) return 13+2*5;else return 0;", 
                    ScriptOptions.Default.AddImports("System","System.IO"));
                MessageBox.Show(scriptState.Result.ReturnValue.ToString());

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
               
            }
        }