Question

At first, I show a login form. When a user enters the correct id and password, I want to show another form, and close the login form. Following is the way I start the login form.

static class Program
{
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new FrmLogin());
    }
}

Now, when I want to show the main form, I call the dispose() method of the FrmLogin class, but the application ends immediately. My solution is changing the visible property of FrmLogin class into false and I know it is not right, please suggest a way for this to work out.

Answer 1

You can show login form as dialog and if login success then you can run main form as:

static class Program
{
     public static bool isValid = false;
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        using (FrmLogin login = new FrmLogin())
        { 
            login.ShowDialog(); 
            if (isValid)
            {           
                Application.Run(new MainForm());
            }
        }
    }
}

in your FrmLogin, validate user and set DialogResult as Ok. Here I did it on button click event.

private void btnLogin_Click(object sender, EventArgs e)
{

    Program.isValid= true; // impliment this as method 
    if(Program.isValid)
    {
      this.DialogResult = DialogResult.OK;
      // or this.Close();
    }
    else
    {
      //else part code
    }
}