数据库之 ：分页技术：之点击一次取一次数据

<Window x:Class="Supplier.UserI"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:Supplier"
        Title="查看用户" Height="500" Width="440" Loaded="Window_Loaded" WindowStartupLocation="CenterScreen">
        <Grid >
        <Grid.Resources>
            <local:TypeConvert x:Key="typeConvert"/>
            <DataTemplate x:Key="oprate" DataType="User">
                <StackPanel Orientation="Horizontal">
                    <Button Tag="{Binding}" Click="updateUser" Content="修改" Background="Gray" Width="40" Foreground="White"/>
                    <Button Tag="{Binding}"  Click="deleteUser" Content="删除" Background="red" Width="40" Foreground="White"/>
                </StackPanel>
            </DataTemplate>
            <!--<DataTemplate x:Key="permis" DataType="User" >
                <ComboBox x:Name="permission" SelectedIndex="{Binding Type}" >
                    <TextBlock Text="所有操作" />
                    <TextBlock Text="查看" Margin="10,0,0,0" />
                </ComboBox>
            </DataTemplate>-->
        </Grid.Resources>
            <Grid.RowDefinitions>
            <RowDefinition Height="50"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="100"/>
        </Grid.RowDefinitions>
        <TextBlock Grid.Row="0" Text="用户管理" VerticalAlignment="Center" HorizontalAlignment="Center" FontSize="18"  FontStyle="Normal" Foreground="Blue"/>
        <Button Click="addUser"   Grid.Row="0" Content="添加" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="0,0,10,0" Background="SkyBlue" Width="50" Foreground="White"/>
<!--Beige-->
        <ListView x:Name="grid" Grid.Row="1" Margin="10,0,10,10">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="序号" Width="60" DisplayMemberBinding="{Binding Number}"/>
                    <GridViewColumn Header="用户名" Width="80" DisplayMemberBinding="{Binding UserName}"/>
                    <GridViewColumn Header="权限" Width="110" DisplayMemberBinding="{Binding Type,Converter={StaticResource typeConvert}}"/> 
                    <GridViewColumn Header="操作" Width="120" CellTemplate="{StaticResource oprate}"/>
                </GridView>
            </ListView.View>
        </ListView>
        <Grid Grid.Row="2">
            <Button Content="上一页" Height="23" HorizontalAlignment="Left" Margin="37,0,0,0" Name="button7" VerticalAlignment="Top" Width="65" Click="PreviousPage" />
            <Button Content="下一页" Height="23" HorizontalAlignment="Left" Margin="108,0,0,0" Name="button8" VerticalAlignment="Top" Width="59" Click="NextPage" />
            <Label Content="转到" Height="28" HorizontalAlignment="Left" Margin="173,0,0,0" Name="label6" VerticalAlignment="Top" />
            <TextBox KeyDown="textBox1_KeyDown" Height="23" HorizontalAlignment="Left" Margin="212,0,0,0" Name="textBox1" VerticalAlignment="Top" Width="53" />
            <Button Content="GO" Height="23" HorizontalAlignment="Left" Margin="298,0,0,0" Name="button9" VerticalAlignment="Top" Width="96" Click="JumpPage" />
            <Label Content="页" Height="28" HorizontalAlignment="Left" Margin="269,0,0,0" Name="label7" VerticalAlignment="Top" />
            <Label Height="28" HorizontalAlignment="Left" Margin="120,40,0,0" Name="label8" VerticalAlignment="Top" Content="【第" />
            <Label Content="1" Height="28" HorizontalAlignment="Left" Margin="157,40,0,0" Name="label1" VerticalAlignment="Top" />
            <Label Content="页】" Height="28" HorizontalAlignment="Left" Margin="176,40,0,0" Name="label10" VerticalAlignment="Top" />
            <Label Content="【共" Height="28" HorizontalAlignment="Left" Margin="242,40,0,0" Name="label11" VerticalAlignment="Top" />
            <Label Content="1" Height="28" HorizontalAlignment="Left" Margin="280,40,0,0" Name="label2" VerticalAlignment="Top" />
            <Label Content="页】" Height="28" HorizontalAlignment="Left" Margin="298,40,0,0" Name="label13" VerticalAlignment="Top" />
        </Grid>

    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Data;

namespace Supplier
{
    /// <summary>
    /// Edit.xaml 的交互逻辑
    /// </summary>
    public partial class UserI : Window
    {
        public int pageSize = Global.PageSize; //每页记录数
        private int recordsum = 0;   //表中记录总数
        private int PageSum = 0;     //总页数 
        private int CurrentPage = 1; //当前页 
        private List<User> CurrentList;

        public UserI()
        {
            InitializeComponent();
            this.Topmost = true;//顶置窗口
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            //pageIndex 当前页的序号
            recordsum = UserManager.getCount();

            //判断总页数
            if (recordsum % pageSize == 0)
                PageSum = recordsum / pageSize;
            else
                PageSum = recordsum / pageSize + 1;

            DataGridBind(CurrentPage);
        }
        #region 用户操作
        private void updateUser(object sender, RoutedEventArgs e)
        {
            UserEdit userEdit = new UserEdit();
            Button bt = e.OriginalSource as Button;
            User u = bt.Tag as User;
            userEdit.user = u;
            userEdit.hasType = true;
            bool? result = userEdit.ShowDialog();
            if (result != null && (bool)result)
            {
                Window_Loaded(sender, e);
                DataGridBind(CurrentPage);
            }
        }
        private void deleteUser(object sender, RoutedEventArgs e)
        {
            if (MessageBox.Show("您确定要删除该用户吗？", "系统提示", MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes)
            {
                UserEdit userEdit = new UserEdit();
                Button bt = e.OriginalSource as Button;
                User u = bt.Tag as User;
                UserManager.delete(u.ID);
                Window_Loaded(sender, e);
                DataGridBind(CurrentPage);
            }
        }

        private void addUser(object sender, RoutedEventArgs e)
        {
            UserAdd userAdd = new UserAdd();
            userAdd.hasType = true;
            bool? result = userAdd.ShowDialog();
            if (result != null && (bool)result)
            {
                Window_Loaded(sender, e);
                DataGridBind(PageSum);
            }
        }
        #endregion
        #region 分页

        private void DataGridBind(int pageIndex)
        {
            if (pageIndex > 0)
            {
                CurrentList = UserManager.getList((pageIndex - 1) * pageSize, pageSize);
                this.grid.ItemsSource = CurrentList;
                CurrentPage = pageIndex;
                label1.Content = CurrentPage;
                label2.Content = PageSum;
            }
        }

        /// <summary>
        /// 上一页
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void PreviousPage(object sender, RoutedEventArgs e)
        {
            if (CurrentPage > 1)
                DataGridBind(CurrentPage - 1);
        }
        /// <summary>
        /// 下一页
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void NextPage(object sender, RoutedEventArgs e)
        {
            if (CurrentPage < PageSum)
                DataGridBind(CurrentPage + 1);
        }
        /// <summary>
        /// 跳转页
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void JumpPage(object sender, RoutedEventArgs e)
        {
            int page = 0;
            if (int.TryParse(textBox1.Text, out page))
            {
                if(page<=PageSum)
                    DataGridBind(page);
                else
                {
                    MessageBox.Show("对不起，您输入的页面超过当前最大页数", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                    this.textBox1.Clear();
                }
            }

        }

        private void textBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
                JumpPage(sender, e);
        }
        #endregion


    }
}

        /// <summary>
        /// 获取第skipNum到（skipNum+pageSize）内的记录
        /// </summary>
        /// <param name="skipNum"></param>
        /// <param name="pageSize"></param>
        /// <returns></returns>
        public static List<User> getList(int skipNum, int pageSize)
        {
            string sql = "select top " + pageSize + " Number= row_number() over(order by id asc), * from Users  where id not in "
                        + "(select top " + skipNum + " id from Users order by id asc) order by id asc";
            DataTable dataTable = DbConHelper.ExecuteDataTable(sql);
            List<User> userList = new List<User>();
            User userModel;
            if (dataTable.Rows.Count > 0)
            {
                int page = skipNum / pageSize+1;
                foreach (DataRow row in dataTable.Rows)
                {
                    userModel = new User()
                    {
                        ID = row["ID"].ToString().Trim(),
                        Number = (int.Parse(row["Number"].ToString().Trim()) * page).ToString(),
                        Password = row["Password"].ToString().Trim(),
                        Type = row["Type"].ToString().Trim(),
                        UserName = row["UserName"].ToString().Trim()

                    };
                    userList.Add(userModel);
                }
            }
            return userList;

        }

        public static int getCount()
        {
            string sql = "select count(*) from Users";
            return (int)DbConHelper.ExecuteScalar(sql);

        }