Dimming inactive forms

Question

When opening Dialog form using Form.ShowDialog() I want to dim the rest of application with a shade of gray.

From my own research it seems that the way to do it is

Answer 1

An alternative to this approach is to use an inherited form instance which hides the showDialog. Then you can disable/enable all forms bar the current one. The code for the dummy form is to deal with the issue described here; Cannot fire form activate event - issue with disabled forms

One of the advantages to this approach is that it requires no change to the normal handling of the showDialog method. Just call it like;

if (dlg.ShowDialog(this) == DialogResult.OK) {
            // etc...
        }

In your inherited form

public abstract class MyBaseForm : XtraForm
{
    private DialogResult setFormsToBackground(Form fParent)
    {
        Form dummyForm = new Form();
        dummyForm.ShowInTaskbar = false;
        dummyForm.FormBorderStyle = FormBorderStyle.None;
        dummyForm.Load += ((object sender, EventArgs e) => { (sender as Form).Size = new Size(0, 0); });

        List
 lstFormsToEnable = new List();
        for (int i = Application.OpenForms.Count - 1; i >= 0; i--)
        {
            try
            {
                Form checkfrm = Application.OpenForms[i];
                if (checkfrm != this && dummyForm != this && checkfrm.Enabled)
                {
                    lstFormsToEnable.Add(checkfrm);
                    checkfrm.Enabled = false;
                }
            }
            catch (Exception ex)
            {

            }
        }
        dummyForm.Show();
        DialogResult result = DialogResult.None;
        if (fParent == null) result = base.ShowDialog();
        else result = base.ShowDialog(fParent);
        for (int i = lstFormsToEnable.Count - 1; i >= 0; i--)
        {
            try
            {
                Form checkfrm = Application.OpenForms[i];
                checkfrm.Enabled = true;
            }
            catch (Exception ex)
            {

            }
        }
        dummyForm.Close();
        return result;
    }
}