row_editing Event is fired on update button click in grid vi

I don't know whats going wrong with me? I have created gridview programmatically as below.

protected void Page_Load(object sender, EventArgs e)
{
GridView gv = new GridView();
gv.ID = pId.ToString();
gv.AutoGenerateEditButton = true;
gv.DataKeyNames = ids;
gv.RowEditing += gv_RowEditing;
gv.RowUpdating += gv_RowUpdating;
bindGv(pId, gv);
}
I have written following methods.

void gv_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridView gv = sender as GridView;
GridViewRow row = (GridViewRow)gv.Rows[e.RowIndex];
ProductCategory pc = context.ProductCategories.First(s => s.Name ==gv.ID );
TextBox txtName = row.FindControl("txtName") as TextBox;
pc.Name = txtName.Text;

}

void gv_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView gv = sender as GridView;
gv.EditIndex = e.NewEditIndex;
bindGv(Convert.ToInt32(gv.ID), gv);
}
But when I run it in debugging mode...clicking on update button invokes gv_RowEditing method instead of gv_RowUpdating....

Please Help.