Active Form Status check

If this is a standard WinForms app (as opposed to an MDI app), there is only one active form unless you have modeless forms open, and that form is the one you're looking at.

Now, if you;'re talking about how many forms are currently *open*, then you have to set the parent property in each form as it is open, which means you have to pass the parent form to the child (I'd do that in the constructor). Once you've done that, you can travers the forms backwards from the current form by cascading each Parent property until you read one that doesn't have a parent specified.

It's kind pointless to want to know the count, but that's how I'd do it.

try this

Form.ActiveForm.ActiveMdiChild

and also as santosh said

Form.ActiveForm.ActiveMdiChild.Close();

I hope I helped
:-)

List<form> forms = new List<form>();
 private void btnForm1_Click(object sender, EventArgs e)
        {
            Form1 frm1 = new Form1(this);
            forms.Add(frm1);
            frm1.Show();
        }
        
        private void btnForm2_Click(object sender, EventArgs e)
        {
            Form2 frm2 = new Form2(this);
            forms.Add(frm2);
            frm2.Show();
        }

        
        private void CloseForms(String FormText)
        {
            int index = -1;
            for (int i = 0; i <= forms.Count - 1; i++)
            {
                if (forms[i].Text ==FormText.Trim())
                {
                    index = i;
                    break;
                }

            }
            if (index != -1)
            {
                Form form = forms[index];
                form.Close();
                forms.RemoveAt(index);
            }
        }

        private void btnForm1Close_Click(object sender, EventArgs e)
        {
            CloseForms("Form1");
        }


        private void btnForm2Close_Click(object sender, EventArgs e)
        {
            
            CloseForms("Form2");
        }