分页查询，很早就听过了，，尤其是在“高校”的项目中更是听得比较多，一直想着自己研究一下，看看到底分页查询有什么神秘之处。但是，一直因为自己在做其他的内容，所以一直没有好好的学习一下。现在，做统计查询的时候，因为查询的数据量比较大，差不多一秒一条数据，甚至是一秒钟600条数据的时间查询，所以不得不采用分页查询了。

我们常说的分页查询分为两种。一种是假分页，也就是一次性的把需要的数据全部查出，然后在显示的时候是分页显示的。这样做的好处就是直观的给用户显示出需要的内容，而不用采用滚动条来滚动查看。另外就是，分页的速度是比较快的。

在这里我主要想总结的就是另一种分页方式——真分页。所谓真分页，就是所见即所得，我们看到的数据，就是我们当前查询到的数据。这样做的好处就是，当我们查询的数据量非常大的时候，比如当我们查询一万条数据的时候，可以非常迅速的查询出先展示给用户的那部分数据，而不用去额外的查询此刻不需要的内容。因此，这样做大大增加了查询的速度，提高了系统的性能，给用户以非常好的用户体验。

以下就是我在项目中做的一个实例代码，供大家参考：

<span style="font-size:24px;"> public ucDataPage() { InitializeComponent(); pIndex = 1; Loaded += delegate { //首页 btnFirst.MouseLeftButtonUp += new MouseButtonEventHandler(btnFirst_Click); //上一页 btnPrev.MouseLeftButtonUp += new MouseButtonEventHandler(btnPrev_Click); //下一页 btnNext.MouseLeftButtonUp += new MouseButtonEventHandler(btnNext_Click); //末页 btnLast.MouseLeftButtonUp += new MouseButtonEventHandler(btnLast_Click); btnGo.Click += new RoutedEventHandler(btnGo_Click); }; } private DataTable _dt = new DataTable(); //每页显示多少条 public static int pageNum = 10; //当前是第几页 public static int pIndex = 1; //对象 public DataGrid grdList; //最大页数 public static int MaxIndex = 1; //总记录数 public static int allNum = 0; public static int Count = 0; /// <summary> /// 初始化数据 /// </summary> /// <param name="grd"></param> /// <param name="ds"></param> /// <param name="Num"></param> public void ShowPages(DataGrid grd, DataTable ds, int Num) { if (ds == null || ds.Rows.Count == 0) { return; } if (ds.Rows.Count == 0) { return; } DataTable dt = ds; _dt = dt.Clone(); grdList = grd; pageNum = Num; pIndex = 1; foreach (DataRow r in dt.Rows) { _dt.ImportRow(r); } SetMaxIndex(); ReadDataTable(); if (MaxIndex > 1) { pageGo.IsReadOnly = false; btnGo.IsEnabled = true; } } /// <summary> /// 画数据 /// </summary> private void ReadDataTable() { DisplayPagingInfo(); } /// <summary> /// 画每页显示等数据 /// </summary> private void DisplayPagingInfo() { if (pIndex == 1) { btnPrev.IsEnabled = false; btnFirst.IsEnabled = false; } else { btnPrev.IsEnabled = true; btnFirst.IsEnabled = true; } if (pIndex == MaxIndex) { btnNext.IsEnabled = false; btnLast.IsEnabled = false; } else { btnNext.IsEnabled = true; btnLast.IsEnabled = true; } tbkRecords.Text = string.Format("每页{0}条/共{1}条", pageNum, allNum); int first = (pIndex - 4) > 0 ? (pIndex - 4) : 1; int last = (first + 9) > MaxIndex ? MaxIndex : (first + 9); grid.Children.Clear(); for (int i = first; i <= last; i++) { ColumnDefinition cdf = new ColumnDefinition(); grid.ColumnDefinitions.Add(cdf); TextBlock tbl = new TextBlock(); tbl.Text = i.ToString(); tbl.Style = FindResource("PageTextBlock3") as Style; tbl.MouseLeftButtonUp += new MouseButtonEventHandler(tbl_MouseLeftButtonUp); tbl.MouseLeftButtonDown += new MouseButtonEventHandler(tbl_MouseLeftButtonDown); if (i == pIndex) { tbl.IsEnabled = false; } Grid.SetColumn(tbl, grid.ColumnDefinitions.Count - 1); Grid.SetRow(tbl, 0); grid.Children.Add(tbl); } } /// <summary> /// 首页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnFirst_Click(object sender, System.EventArgs e) { pIndex = 1; RaisePageChanged(); ReadDataTable(); } /// <summary> /// 首页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnFirst_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { e.Handled = true; } /// <summary> /// 上一页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnPrev_Click(object sender, System.EventArgs e) { if (pIndex <= 1) { return; } pIndex--; RaisePageChanged(); ReadDataTable(); } /// <summary> /// 上一页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnPrev_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { e.Handled = true; RaisePageChanged(); } /// <summary> /// 下一页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnNext_Click(object sender, System.EventArgs e) { if (pIndex >= MaxIndex) { return; } pIndex++; RaisePageChanged(); ReadDataTable(); } /// <summary> /// 下一页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnNext_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { e.Handled = true; } /// <summary> /// 末页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnLast_Click(object sender, System.EventArgs e) { pIndex = MaxIndex; RaisePageChanged(); ReadDataTable(); } /// <summary> /// 末页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnLast_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { e.Handled = true; } /// <summary> /// 设置最大页 /// </summary> private void SetMaxIndex() { //多少页 int Pages = Count / pageNum; if (Count != (Pages * pageNum)) { if (Count < (Pages * pageNum)) { Pages--; } else { Pages++; } MaxIndex = Pages; allNum = _dt.Rows.Count; } } /// <summary> /// 跳转到多少页 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnGo_Click(object sender, RoutedEventArgs e) { if (IsNumber(pageGo.Text)) { int pageNum = int.Parse(pageGo.Text); if (pageNum > 0 && pageNum <= MaxIndex) { pIndex = pageNum; RaisePageChanged(); ReadDataTable(); } else if (pageNum > MaxIndex) { pIndex = MaxIndex; RaisePageChanged(); ReadDataTable(); } } pageGo.Text = ""; } /// <summary> /// 分页数字的点击触发事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void tbl_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) { TextBlock tbl = sender as TextBlock; if (tbl == null) { return; } int index = int.Parse(tbl.Text.ToString()); pIndex = index; if (index > MaxIndex) { pIndex = MaxIndex; } if (index < 1) { pIndex = 1; } RaisePageChanged(); ReadDataTable(); } void tbl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { e.Handled = true; } private static Regex RegNumber = new Regex("^[0-9]+$"); /// <summary> /// 判断是否为数字 /// </summary> /// <param name="valString"></param> /// <returns></returns> public static bool IsNumber(string valString) { Match m = RegNumber.Match(valString); return m.Success; } #region 字段、属性、委托 public delegate void PageChangedEventHandler(object sender, PageChangedEventArgs args); private PageChangedEventArgs pageChangedEventArgs; #endregion /// <summary> /// 引发分页更改事件 /// </summary> private void RaisePageChanged() { if (pageChangedEventArgs == null) { pageChangedEventArgs = new PageChangedEventArgs(PageChangedEvent, pageNum, pIndex); } else { pageChangedEventArgs.PageSize = pageNum; pageChangedEventArgs.PageIndex = pIndex; } RaiseEvent(pageChangedEventArgs); } public static readonly RoutedEvent PageChangedEvent = EventManager.RegisterRoutedEvent("PageChanged", RoutingStrategy.Bubble, typeof(PageChangedEventHandler), typeof(ucDataPage)); public class PageChangedEventArgs : RoutedEventArgs { public int PageSize { get; set; } public int PageIndex { get; set; } public PageChangedEventArgs(RoutedEvent routeEvent, int pageSize, int pageIndex) : base(routeEvent) { PageSize = pageSize; PageIndex = pageIndex; } } public event PageChangedEventHandler PageChanged { add { AddHandler(PageChangedEvent, value); } remove { RemoveHandler(PageChangedEvent, value); } } } }</span>