wpf-DataGrid分页

xaml：

  <Grid>


        <DataGrid AutoGenerateColumns="False" Height="148" HorizontalAlignment="Left" Margin="27,21,0,0" Name="dataGrid1" VerticalAlignment="Top" Width="380" IsReadOnly="True" CanUserAddRows="False" VerticalScrollBarVisibility="Auto" SelectionMode="Single"  EnableRowVirtualization="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Id" Binding="{Binding Path=Id}" />
                <DataGridTextColumn Header="Name" Binding="{Binding Path=Name}" />
                <DataGridTextColumn Header="Age" Binding="{Binding Path=Age}" />
                <DataGridTextColumn Header="ClassId" Binding="{Binding Path=ClassId}" />
                <DataGridTextColumn Header="Birthday" Binding="{Binding Path=Birthday}" />
            </DataGrid.Columns>
        </DataGrid>
      
            <Button Content="上一页" Height="23" HorizontalAlignment="Left" Margin="37,185,0,0" Name="button7" VerticalAlignment="Top" Width="65" Click="button7_Click" />
            <Button Content="下一页" Height="23" HorizontalAlignment="Left" Margin="108,185,0,0" Name="button8" VerticalAlignment="Top" Width="59" Click="button8_Click" />
            <Label Content="转到" Height="28" HorizontalAlignment="Left" Margin="173,186,0,0" Name="label6" VerticalAlignment="Top" />
            <TextBox Height="23" HorizontalAlignment="Left" Margin="212,187,0,0" Name="textBox1" VerticalAlignment="Top" Width="53" />
            <Button Content="GO" Height="23" HorizontalAlignment="Left" Margin="298,185,0,0" Name="button9" VerticalAlignment="Top" Width="96" Click="button9_Click" />
            <Label Content="页" Height="28" HorizontalAlignment="Left" Margin="269,185,0,0" Name="label7" VerticalAlignment="Top" />
            <Label Height="28" HorizontalAlignment="Left" Margin="120,228,0,0" Name="label8" VerticalAlignment="Top" Content="【第" />
            <Label Content="1" Height="28" HorizontalAlignment="Left" Margin="157,228,0,0" Name="label1" VerticalAlignment="Top" />
            <Label Content="页】" Height="28" HorizontalAlignment="Left" Margin="176,228,0,0" Name="label10" VerticalAlignment="Top" />
            <Label Content="【共" Height="28" HorizontalAlignment="Left" Margin="242,228,0,0" Name="label11" VerticalAlignment="Top" />
            <Label Content="1" Height="28" HorizontalAlignment="Left" Margin="280,228,0,0" Name="label2" VerticalAlignment="Top" />
            <Label Content="页】" Height="28" HorizontalAlignment="Left" Margin="298,228,0,0" Name="label13" VerticalAlignment="Top" />
      
    </Grid>

后台代码：

 public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
        MySqlDataAdapter msda;
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            DataGridBind(Convert.ToInt32(label1.Content));

        }
        public const int pageSize = 5;
        DataTable dt;


        private void DataGridBind(int pageIndex)
        {
            String connetStr = "Database=alexDB;server=localhost;User Id=root;Password=alex199314;pooling=false;CharSet=utf8;port=3306";
           
            MySqlConnection conn = new MySqlConnection(connetStr);
            try
            {
                conn.Open();//打开通道，建立连接，可能出现异常,使用try catch语句
                msda = new MySqlDataAdapter("select * from Student ", conn);
                dt = new DataTable();
                msda.Fill(dt);
             

            }
            catch (MySqlException ex)
            {
                //Console.WriteLine(ex.Message);
                MessageBox.Show(ex.Message);
            }
            finally
            {
                conn.Close();
            }
            //pageIndex 当前页的序号
            int recordsum = 0;   //表中记录总数
            int PageSum = 0;     //总页数         


            var query = from title in dt.AsEnumerable()
                        select title;
      
            recordsum = query.Count();
   
            //判断总页数
            if (recordsum % pageSize == 0)
                PageSum = recordsum / pageSize;
            else
                PageSum = recordsum / pageSize + 1;


            dataGrid1.ItemsSource = query.Skip((pageIndex - 1) * pageSize).Take(pageSize).CopyToDataTable<DataRow>().DefaultView; ;


            label1.Content = Convert.ToString(pageIndex);
            label2.Content = Convert.ToString(PageSum);
        }


        private void button7_Click(object sender, RoutedEventArgs e)
        {
            //上一页
            if (Convert.ToInt32(label1.Content) > 1)
                DataGridBind(Convert.ToInt32(label1.Content) - 1);

        }

        private void button8_Click(object sender, RoutedEventArgs e)
        {
            //下一页
            if (Convert.ToInt32(label1.Content) < Convert.ToInt32(label2.Content))
                DataGridBind(Convert.ToInt32(label1.Content) + 1);
        }


        private void button9_Click(object sender, RoutedEventArgs e)
        {
            //调转到第n页
            if (Convert.ToInt32(textBox1.Text) >= 1 && Convert.ToInt32(textBox1.Text) <= Convert.ToInt32(label2.Content))
                DataGridBind(Convert.ToInt32(textBox1.Text));

        }
    }