VS中在窗体项目中打开控制台进行打印调试

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
#if DEBUG //DEBUG模式下
using System.Runtime.InteropServices;
using System.Threading;
#endif

namespace WindowsFormsDataBaseApp
{

    static class Program
    {

#if DEBUG  //DEBUG模式下加载控制台库
        /// <summary>
        /// 创建控制台窗口
        /// </summary>
        /// <returns></returns>
        [DllImport("kernel32.dll")]
        public static extern bool AllocConsole();

        /// <summary>
        /// 释放控制台窗口
        /// </summary>
        /// <returns></returns>
        [DllImport("kernel32.dll")]
        public static extern bool FreeConsole();
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
#endif
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
#if DEBUG //DEBUG模式下打开控制台
            AllocConsole();
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());

            Console.WriteLine("Main running");
            Console.ReadLine();
            FreeConsole();
#else
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
#endif
        }
    }
}