问获取错误：“等待不能用作异步方法或lambda表达式中的标识符”

EN

int pagenumber = 1;

  public async Task<IPagedList<GetBillMani_Result>> GetPagedListAsync(int pagenumber = 1, int pageSize = 10)
    {
        return await Task.Factory.StartNew(() => 
        {
            using (ManiJayBharatEntities entity = new ManiJayBharatEntities())
            {
                var a = 15;
                return entity.GetBillMani(a, a).OrderBy(m => m.Name).ToPagedList(pagenumber, pageSize);
            }
        });
    }

private async void AllBill_Load(object sender, EventArgs e)
    {
        list = await.GetPagedListAsync();  // <- getting error here
        btnPrev.Enabled = list.HasPreviousPage;
        btnNext.Enabled = list.HasNextPage;
        dataGridView1.DataSource = list.ToList();
        label3.Text = string.Format("Page {0}/{1}", pagenumber, list.PageCount);
    }