Opening the new form and closing the previous

Question

Hi ,

In my project i am stuck at a point and can not figure out how to open a new form inside a panel of already opened form . So there is a form named father and it has a panel . i am using this panel to open all subsequent forms (children) . there are two problems i am facing

1. before the new form is opened , i have to check whether a new form is already opened or not inside the fathers panel . if yes a form is already opened inside panel , it should close first and then only the new child can open .

Answer 1

Hi @Shaifali jain , Welcome to Microsoft Q&A.

Your premise is to close the previous form. You only need to use a simple method to determine whether Panel.Controls.Count is 0, and then use the built-in clear().

private void button1_Click(object sender, EventArgs e)
{
    if (FatherPanel.Controls.Count != 0)
    {
        FatherPanel.Controls.Clear();
    }

    // Add new subform after clearing
    ChildForm newChildForm = new ChildForm();
    newChildForm.TopLevel = false;
    FatherPanel.Controls.Add(newChildForm);
    newChildForm.Show();
}

Best Regards,

Jiale

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Answer 2

I made sample

        private void button1_Click(object sender, EventArgs e) {
            RecreateForm<Form2>();
        }

        private void RecreateForm<T>() where T : Form, new() {
            foreach (T oldForm in 
                        FatherPanel.Controls.OfType<T>().ToArray()) {
                using (oldForm) {
                    oldForm.Close();
                    FatherPanel.Controls.Remove(oldForm);
                }
            }
            var newForm = new T {
                TopLevel = false,
                Visible = true
            };
            FatherPanel.Controls.Add(newForm);
        }