Form that was specified to be the MdiParent for this form is not an MdiContainer

Question

I was working on an inventory software and suddenly came to know that I need some main form through which I should open all the other forms, so I created one named frmMainPanel and use a menu strip to link it to another I am successful in linking them but they are opening outside the main form, I use following code to link them

Linking frmSaleInvoice form using:

frmSaleInvoice childForm = new frmSaleInvoice();
cs.show()

now i realize i should make them child to the main form so i tried that using following code:

frmSaleInvoice childForm = new frmSaleInvoice();

childForm.MdiParent = this;
childForm.Show();

but it says **" Form that was specified to be the MdiParent for this form is not an MdiContainer."**

can any one help me out wher i am mistaking and how could i make a form named frmSaleInvoice to child of other form named frmMainPanel

Answer 1

The Mdi parent must have it's IsMdiContainer property set to True. You can set this property at design time in your frmMainPanel form.

Answer 2

You should set the IsMdiContainer = true for the parent form.

Answer 3

you don't have to set the childForm to true, you can try this:

childForm.MdiParent = (name of your mdiparent form).ActiveForm;
childForm.Show();

Answer 4

Just write IsMdiContainer = true; in your code.

Form2 fL = new Form2();
fL.MdiParent = this;
fL.Show();

Form2 is the name of the form that you want to show.

Answer 5

private void tsbCadastrar_Click(object sender, EventArgs e)
    {
        try
        {
            frmCliente cliente = null;
            foreach (Form frm in this.MdiChildren)
            {
                if (frm is frmCliente)
                {
                    cliente = (frmCliente)frm;
                    break;
                }
            } 
            if (cliente == null)
            {
                cliente = new frmCliente();
                cliente.MdiParent = this; //Remove this line in case the IsMdiParent = True 
                cliente.Show();
            }
            cliente.Focus();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Não foi possivel se conectar ao formulario devido ao erro: " + ex.Message,
                "Aviso",
                MessageBoxButtons.OK,
                MessageBoxIcon.Information);
        }
    }