DataTable dogTable = new DataTable();

void dogTableAdd(string name, string caption, bool readOnly)
{
	var n_sch = dogTable.Columns.Add(name, typeof(string));
	n_sch.Caption = caption;
	//n_sch.ReadOnly = readOnly;
}

dogTableAdd("t1", "тест", true);
dogTableAdd("t2", "тест 2", true);

dogTable.NewRow();
dogTable.Rows.Add(t1var, t2var);

grid.ItemsSource = dogTable.DefaultView;

grid.Columns[0].Header = "d"; // ошибка