private void btnDuzenle_Click(object sender, EventArgs e)
{
Category guncelKat = new Category();
guncelKat.CategoryName = txtKatAdi.Text;
guncelKat.Description = txtAciklama.Text;
guncelKat.CategoryID = id;
katRep.Duzenle(guncelKat);
dataGridView1.DataSource = katRep.Listele();
}