private void button1_Click(object sender, EventArgs e) { try { string username = textBoxUsername.Text; string password = textBoxPasswd.Text; int acessLevel = ((comboBoxAcessLevel.SelectedItem) as ComboboxItem).GetItemValue(); Classes.Usuario u = new Classes.Usuario(0, username, password, acessLevel); if (adapter.adicionarUsuario(u)) { MessageBox.Show("Adicionado!", "Sucesso", MessageBoxButtons.OK, MessageBoxIcon.Information); this.Close(); } else { MessageBox.Show("Falha", "Erro", MessageBoxButtons.OK, MessageBoxIcon.Error); } } catch (NullReferenceException) { MessageBox.Show("Verifique se os campos estão preenchidos corretamente", "Erro", MessageBoxButtons.OK, MessageBoxIcon.Error); } }