Devexpress for WPF Grid分页

 public DataPager()
        {
            InitializeComponent();
            cboPageSize.SelectionChanged += cboPageSize_SelectionChanged;
        }
        public delegate void BackToCallback(int start, int num, ref int count);
        public event BackToCallback OnPageGetList;

        public int pageIndex = 1;
        public int num = 100;
        public int PageCount = 1;
        public int count;

        void cboPageSize_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            try
            {

                ComboBoxItem cbb = cboPageSize.SelectedItem as ComboBoxItem;
                num = Convert.ToInt32(cbb.Content);
                int iEnd = count % num == 0 ? count / num : count / num + 1;
                pageIndex = Convert.ToInt32(txtJumpPage.Text);
                if (pageIndex > iEnd)
                {
                    pageIndex = iEnd;
                }

                DgvListBind(pageIndex, num, ref  count);
                ImgControl(pageIndex, count);

            }
            catch (Exception ex)
            {
            }
        }

        private void DgvListBind(int pageIndex, int num, ref int count)
        {
            if (OnPageGetList != null)
            {
                int start = (pageIndex - 1) * num;
                OnPageGetList(start, num, ref count);
                if (count == 0)
                {
                    lblPageCount.Content = "1";
                    lblTotal.Content = count.ToString();
                }
                else
                {
                    lblPageCount.Content = (count % num == 0 ? count / num : count / num + 1).ToString();
                    lblTotal.Content = count.ToString();
                }
            }
        }

        private void ImgControl(int pageIndex, int pageCount)
        {
            pageCount = pageCount / num == 0 ? pageCount / num : (pageCount / num) + 1;
            if (pageIndex <= 1 && pageCount <= 1)
            {
                btnFirst.IsEnabled = false;
                btnLeft.IsEnabled = false;
                btnRight.IsEnabled = false;
                btnLast.IsEnabled = false;
            }
            else if (pageIndex == 1 && pageCount > 1)
            {
                btnFirst.IsEnabled = false;
                btnLeft.IsEnabled = false;
                btnRight.IsEnabled = true;
                btnLast.IsEnabled = true;
            }
            else if (pageIndex > 1 && pageIndex < pageCount)
            {
                btnFirst.IsEnabled = true;
                btnLeft.IsEnabled = true;
                btnRight.IsEnabled = true;
                btnLast.IsEnabled = true;
            }
            else if (pageIndex > 1 && pageIndex == pageCount)
            {
                btnFirst.IsEnabled = true;
                btnLeft.IsEnabled = true;
                btnRight.IsEnabled = false;
                btnLast.IsEnabled = false;
            }
        }

        public void btnFirst_Click(object sender, RoutedEventArgs e)
        {
            pageIndex = 1;
            txtJumpPage.Text = "1";
            num = Convert.ToInt32(cboPageSize.Text);
            DgvListBind(pageIndex, num, ref  count);
            ImgControl(pageIndex, count);
        }

        private void btnLeft_Click(object sender, RoutedEventArgs e)
        {
            pageIndex -= 1;
            txtJumpPage.Text = pageIndex.ToString();
            num = Convert.ToInt32(cboPageSize.Text);
            DgvListBind(pageIndex, num, ref  count);
            ImgControl(pageIndex, count);
        }

        private void btnRight_Click(object sender, RoutedEventArgs e)
        {
            pageIndex += 1;
            txtJumpPage.Text = pageIndex.ToString();
            num = Convert.ToInt32(cboPageSize.Text);
            DgvListBind(pageIndex, num, ref  count);
            ImgControl(pageIndex, count);
        }

        private void btnLast_Click(object sender, RoutedEventArgs e)
        {
            num = Convert.ToInt32(cboPageSize.Text);
            pageIndex = count % num == 0 ? count / num : count / num + 1;
            DgvListBind(pageIndex, num, ref  count);
            //也许有新数据所以要更新
            pageIndex = count % num == 0 ? count / num : count / num + 1;
            txtJumpPage.Text = pageIndex.ToString();
            DgvListBind(pageIndex, num, ref  count);
            ImgControl(pageIndex, count);
        }

        private void btnJump_Click(object sender, RoutedEventArgs e)
        {
            int index = 0;
            try
            {
                index = Convert.ToInt32(txtJumpPage.Text);
            }
            catch (Exception ex)
            {
                MessageBox.Show("请输入数字!");
                return;
            }
            num = Convert.ToInt32(cboPageSize.Text);
            int end = count % num == 0 ? count / num : count / num + 1;
            if (index > end)
            {
                index = end;
                txtJumpPage.Text = end.ToString();
            }
            pageIndex = index;
            DgvListBind(pageIndex, num, ref  count);
            txtJumpPage.Text = pageIndex.ToString();
            DgvListBind(pageIndex, num, ref  count);
            ImgControl(pageIndex, count);
        }

        /// <summary>
        /// 刷新
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void btnRefresh_Click(object sender, RoutedEventArgs e)
        {
            DgvListBind(pageIndex, num, ref  count);
        }