How to Implement login form and main form without more instances in c#

Question

Iam creating an instance to the main form on login button click and again creating instance to login form on logout button click. my code is

      if ((txtU         


        

Answer 1

You need to put your login part in Program.cs , before Application.Run() called e.g :

 if (new frmLogin().ShowDialog() == DialogResult.OK)
 {
     Application.Run(new frmMain());
 }

then put login codes in login form. after user logged in, form login will be closed and will set this.dialogresualt = dialogresult.ok; e.g :

if (txtUserName.Text == "blah"
      && txtPassword.Text == "blah")
   {
     txtPassword.BackColor = Color.YellowGreen;
     txtUserName.BackColor = Color.YellowGreen;
     this.DialogResult = DialogResult.OK;
   }
   else
   {
     txtPassword.BackColor = Color.Salmon;
     txtUserName.BackColor = Color.Salmon;
    }