在kernel32.dll导入控制台的两个方法：AllocConsole()+FreeConsole()

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

static class Program
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>

        [DllImport("kernel32.dll")]
        static extern bool FreeConsole();
        [DllImport("kernel32.dll")]
        public static extern bool AllocConsole();
        [STAThread]
        static void Main()
        {
            AllocConsole();//调用系统API，调用控制台窗口

            Console.WriteLine("Hello World");
            Console.ReadKey();

            FreeConsole();//释放控制台

            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            SqlServerString.SqlConnectString = "LTKDB";
            Application.Run(new Form1());
        }
    }