调试易

以下是Program.cs的代码
static class Program
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Simulate sim = new Simulate();
            Process current = Process.GetCurrentProcess();
            bool newinstance = true;
            Process[] processes = Process.GetProcessesByName(current.ProcessName);            //遍历正在有相同名字运行的例程
            foreach (Process process in processes)
            {
                //忽略现有的例程  
                if (process.Id != current.Id)
                {
                    //确保例程从EXE文件运行  
                    if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == current.MainModule.FileName)
                    {
                        //返回另一个例程实例  
                        current = process;
                        newinstance = false;
                        break;
                    }
                }
            }
            if (newinstance)
            {
                Application.Run(sim);
            }
            else
            {
                ShowWindowAsync(current.MainWindowHandle, 1);                //设置真实例程为foreground   window  
                SetForegroundWindow(current.MainWindowHandle);
            }
        }        [DllImport("User32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);        [DllImport("User32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);
    }

Error 1 The type or namespace name 'DllImport' could not be found (are you missing a using directive or an assembly reference?) E:\wwwroot\newcaigou\WindowsApplication1\Program.cs 56 10 WindowsApplication1
Error 2 The type or namespace name 'DllImport' could not be found (are you missing a using directive or an assembly reference?) E:\wwwroot\newcaigou\WindowsApplication1\Program.cs 59 10 WindowsApplication1

似乎要加哪个 using ？

using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Reflection;