Question

How would you make an instance of a form open itself in a Modal way?

I tried this.ShowDialog() but it doesn’t make the form appear modal (you can still access other forms). I guess this is because it is it’s own parent form in if it shows itself, but I’m not sure.

My problem:

I have an application made of 2 forms:

1. MainForm
2. LoginForm

MainForm creates an instance of and opens LoginForm to ask the user to authenticate. LoginForm has a timer to regularly check and log the user in – I want this timer to open LoginForm modally. I know this could be achieved by putting the timer in MainForm but I would like to know how to make a form ShowDialog() an instance of itself.

Thanks in advance.

Answer 1

Make sure you call ShowDialog after InitializeComponent:

public newForm()
{
    InitializeComponent();
    this.ShowDialog();
}

MY TEST

I made new class named Form2:

public partial class Form2 : Form
{
    public Form2()
    {
        //this may not call in constractor 
        //InitializeComponent();
    }

    public void ShowModalForm()
    {
        InitializeComponent();
        ShowDialog();
    }
}

and start it on main without any parent and it starts modally:

static class Program
{
    [STAThread]
    static void Main()
    {
        new Form2().ShowModalForm();
        //Application.Run(new Form1());
    }
}