Question

I have problem with show or hide form in Window Form Application.

I start first running loginform at program.cs ( Application.Run(new loginform());), when login success, then show another form ( Main Interface ) and I want to close or hide loginform when second form is shown, but it is not working.

I don know how to do it. Is it a Thread related problem or not?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace Myapp
{
   static class Program
   {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {

            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Loginfrm());

        }
    }
}

Answer 1

You could add a property to your Loginfrm class indicating if login was sucessfull or not.
Then, after closing the your Loginfrm, you could start another message loop.

Example:

static void Main()
{
    Application.EnableVisualStyles();
    Application.SetCompatibleTextRenderingDefault(false);
    Loginfrm login = new Loginfrm(); 
    Application.Run(login);
    if (login.LogInSuccesfull)
        Application.Run(new MainForm());
}