asp.net中让Repeater和GridView支持DataPager分页

using System.Web.UI;

using System.Web.UI.WebControls;

namespace WYJ.Web.Controls

{

/// <summary>

/// Repeater with support for DataPager

/// </summary>

[ToolboxData("<{0}:DataPagerRepeater runat=server PersistentDataSource=true></{0}:DataPagerRepeater>")]
public class DataPagerRepeater : Repeater, System.Web.UI.WebControls.IPageableItemContainer, INamingContainer

{

/// <summary>

/// Number of rows to show

/// </summary>

public int MaximumRows { get { return ViewState["MaximumRows"] != null ? (int)ViewState["MaximumRows"] : -1; } }

/// <summary>

/// First row to show

/// </summary>

public int StartRowIndex { get { return ViewState["StartRowIndex"] != null ? (int)ViewState["StartRowIndex"] : -1; } }

/// <summary>

/// Total rows. When PagingInDataSource is set to true you must get the total records from the datasource (without paging) at the FetchingData event

/// When PagingInDataSource is set to true you also need to set this when you load the data the first time.

/// </summary>

public int TotalRows { get { return ViewState["TotalRows"] != null ? (int)ViewState["TotalRows"] : -1; } set { ViewState["TotalRows"] = value; } }

/// <summary>

/// If repeater should store data source in view state. If false you need to get and bind data at post back. When using a connected data source this is handled by the data source.

/// </summary>

public bool PersistentDataSource

{

get { return ViewState["PersistentDataSource"] != null ? (bool)ViewState["PersistentDataSource"] : true; }

set { ViewState["PersistentDataSource"] = value; }

}

/// <summary>

/// Set to true if you want to handle paging in the data source.

/// Ex if you are selecting data from the database and only select the current rows

/// you must set this property to true and get and rebind data at the FetchingData event.

/// If this is true you must also set the TotalRecords property at the FetchingData event.

/// </summary>

/// <seealso cref="FetchingData"/>

/// <seealso cref="TotalRows"/>

public bool PagingInDataSource

{

get { return ViewState["PageingInDataSource"] != null ? (bool)ViewState["PageingInDataSource"] : false; }

set { ViewState["PageingInDataSource"] = value; }

}

/// <summary>

/// Checks if you need to rebind data source at postback

/// </summary>

public bool NeedsDataSource

{

get

{

if (PagingInDataSource)

return true;

if (IsBoundUsingDataSourceID == false && !Page.IsPostBack)

return true;

if (IsBoundUsingDataSourceID == false && PersistentDataSource == false && Page.IsPostBack)

return true;

else

return false;

}

}

/// <summary>

/// Loading ViewState

/// </summary>

/// <param name="savedState"></param>

protected override void LoadViewState(object savedState)

{

base.LoadViewState(savedState);

//if (Page.IsPostBack)

//{

// if (!IsBoundUsingDataSourceID && PersistentDataSource && ViewState["DataSource"] != null)

// {

// this.DataSource = ViewState["DataSource"];

// this.DataBind(true);

// }

// if (IsBoundUsingDataSourceID)

// {

// this.DataBind();

// }

//}

}

protected override void OnLoad(System.EventArgs e)

{

if (Page.IsPostBack)

{

if (NeedsDataSource && FetchingData != null)

{

if (PagingInDataSource)

{

SetPageProperties(StartRowIndex, MaximumRows, true);

}

FetchingData(this, null);

}

if (!IsBoundUsingDataSourceID && PersistentDataSource && ViewState["DataSource"] != null)

{

this.DataSource = ViewState["DataSource"];

this.DataBind();

}

if (IsBoundUsingDataSourceID)

{

this.DataBind();

}

}

base.OnLoad(e);

}

/// <summary>

/// Method used by pager to set totalrecords

/// </summary>

/// <param name="startRowIndex">startRowIndex</param>

/// <param name="maximumRows">maximumRows</param>

/// <param name="databind">databind</param>

public void SetPageProperties(int startRowIndex, int maximumRows, bool databind)

{

ViewState["StartRowIndex"] = startRowIndex;

ViewState["MaximumRows"] = maximumRows;

if (TotalRows > -1)

{

if (TotalRowCountAvailable != null)

{

TotalRowCountAvailable(this, new PageEventArgs((int)ViewState["StartRowIndex"], (int)ViewState["MaximumRows"], TotalRows));

}

}

}

/// <summary>

/// OnDataPropertyChanged

/// </summary>

protected override void OnDataPropertyChanged()

{

if (MaximumRows != -1 || IsBoundUsingDataSourceID)

{

this.RequiresDataBinding = true;

}

base.OnDataPropertyChanged();

}

/// <summary>

/// Renders only current items selected by pager

/// </summary>

/// <param name="writer"></param>

protected override void RenderChildren(HtmlTextWriter writer)

{

if (!PagingInDataSource && MaximumRows != -1)

{

foreach (RepeaterItem item in this.Items)

{

if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)

{

item.Visible = false;

if (item.ItemIndex >= (int)ViewState["StartRowIndex"] && item.ItemIndex < ((int)ViewState["StartRowIndex"] + (int)ViewState["MaximumRows"]))

{

item.Visible = true;

}

}

else

{

item.Visible = true;

}

}

}

base.RenderChildren(writer);

}

/// <summary>

/// Get Data

/// </summary>

/// <returns></returns>

protected override System.Collections.IEnumerable GetData()

{

System.Collections.IEnumerable dataObjects = base.GetData();

if (dataObjects == null && this.DataSource != null)

{

if (this.DataSource is System.Collections.IEnumerable)

dataObjects = (System.Collections.IEnumerable)this.DataSource;

else

dataObjects = ((System.ComponentModel.IListSource)this.DataSource).GetList();

}

if (!PagingInDataSource && MaximumRows != -1 && dataObjects != null)

{

int i = -1;

if (dataObjects != null)

{

i = 0;

foreach (object o in dataObjects)

{

i++;

}

}

ViewState["TotalRows"] = i;

if (!IsBoundUsingDataSourceID && PersistentDataSource)

ViewState["DataSource"] = this.DataSource;

SetPageProperties(StartRowIndex, MaximumRows, true);

}

if (PagingInDataSource && !Page.IsPostBack)

{

SetPageProperties(StartRowIndex, MaximumRows, true);

}

return dataObjects;

}

/// <summary>

/// Event when pager/repeater have counted total rows

/// </summary>

public event System.EventHandler<PageEventArgs> TotalRowCountAvailable;

/// <summary>

/// Event when repeater gets the data on postback

/// </summary>

public event System.EventHandler<PageEventArgs> FetchingData;

}

}

<%@ Register Assembly="WYJ.Web.Controls" Namespace="WYJ.Web.Controls" TagPrefix="WYJ" %>

<WYJ:DataPagerRepeater ID="rptLeaveword" runat="server" PersistentDataSource="true">

<ItemTemplate>

<div class="leavewordentry">

<div class="datebox">

<div class="time">

<%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Posttime.ToString("HH:mm") %></div>

<div class="day">

<%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Posttime.ToString("dd") %>

</div>

<div class="month">

<%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Posttime.ToString("MMM", new CultureInfo("en-US")).ToUpper() %><%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Posttime.ToString(" yyyy") %></div>

</div>

<div class="contentbox">

<h2 class="username">

<a id="<%# GeekStudio.Common.IdEncryptor.EncodeId(((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Id) %>"

name="<%# GeekStudio.Common.IdEncryptor.EncodeId(((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Id) %>">

<%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Username %></a></h2>

<div class="lvwordcontent">

<%# ((GeekStudio.ORM.Model.Leaveword)Container.DataItem).Content %>

</div>

</div>

</div>

</ItemTemplate>

</WYJ:DataPagerRepeater>

<div class="pager">

<div class="fr">

共<%=Math.Ceiling((double)DataPager1.TotalRowCount / DataPager1.PageSize)%>页，<%=DataPager1.TotalRowCount%>条记录，每页显示

<asp:LinkButton ID="lnkbtn10" CssClass="currentpagesize" runat="server" OnClick="lnkbtn10_Click">10</asp:LinkButton>

<asp:LinkButton ID="lnkbtn20" runat="server" OnClick="lnkbtn20_Click">20</asp:LinkButton>

<asp:LinkButton ID="lnkbtn30" runat="server" OnClick="lnkbtn30_Click">30</asp:LinkButton>

</div>

<asp:DataPager ID="DataPager1" PagedControlID="rptLeaveword" runat="server">

<Fields>

<asp:NextPreviousPagerField ShowFirstPageButton="True" ShowNextPageButton="False"

ShowPreviousPageButton="False" FirstPageText="首页" />

<asp:NextPreviousPagerField ShowNextPageButton="False" ButtonType="Image" PreviousPageImageUrl="~/Images/icons/pagerprevious.png" />

<asp:NumericPagerField CurrentPageLabelCssClass="current" />

<asp:NextPreviousPagerField ShowPreviousPageButton="False" ButtonType="Image" NextPageImageUrl="~/Images/icons/pagernext.png" />

<asp:NextPreviousPagerField ShowLastPageButton="True" ShowNextPageButton="False"

ShowPreviousPageButton="False" LastPageText="尾页" />

</Fields>

</asp:DataPager>

</div>

protected void lnkbtn10_Click(object sender, EventArgs e)

{

DataPager1.PageSize = 10;

lnkbtn10.CssClass = "currentpagesize";

lnkbtn20.CssClass = "";

lnkbtn30.CssClass = "";

}

protected void lnkbtn20_Click(object sender, EventArgs e)

{

DataPager1.PageSize = 20;

lnkbtn20.CssClass = "currentpagesize";

lnkbtn10.CssClass = "";

lnkbtn30.CssClass = "";

}

protected void lnkbtn30_Click(object sender, EventArgs e)

{

DataPager1.PageSize = 30;

lnkbtn30.CssClass = "currentpagesize";

lnkbtn10.CssClass = "";

lnkbtn20.CssClass = "";

}

using System;

using System.Collections;

using System.Web.UI.WebControls;

namespace WYJ.Web.Controls

{

/// <summary>

/// DataPagerGridView is a custom control that implements GrieView and IPageableItemContainer

/// </summary>

public class DataPagerGridView : GridView, IPageableItemContainer

{

public DataPagerGridView()

: base()

{

PagerSettings.Visible = false;

}

/// <summary>

/// TotalRowCountAvailable event key

/// </summary>

private static readonly object EventTotalRowCountAvailable = new object();

/// <summary>

/// Call base control's CreateChildControls method and determine the number of rows in the source

/// then fire off the event with the derived data and then we return the original result.

/// </summary>

/// <param name="dataSource"></param>

/// <param name="dataBinding"></param>

/// <returns></returns>

protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)

{

int rows = base.CreateChildControls(dataSource, dataBinding);

// if the paging feature is enabled, determine the total number of rows in the datasource

if (this.AllowPaging)

{

// if we are databinding, use the number of rows that were created, otherwise cast the datasource to an Collection and use that as the count

int totalRowCount = dataBinding ? rows : ((ICollection)dataSource).Count;

// raise the row count available event

IPageableItemContainer pageableItemContainer = this as IPageableItemContainer;

this.OnTotalRowCountAvailable(new PageEventArgs(pageableItemContainer.StartRowIndex, pageableItemContainer.MaximumRows, totalRowCount));

// make sure the top and bottom pager rows are not visible

if (this.TopPagerRow != null)

this.TopPagerRow.Visible = false;

if (this.BottomPagerRow != null)

this.BottomPagerRow.Visible = false;

}

return rows;

}

/// <summary>

/// Set the control with appropriate parameters and bind to right chunk of data.

/// </summary>

/// <param name="startRowIndex"></param>

/// <param name="maximumRows"></param>

/// <param name="databind"></param>

void IPageableItemContainer.SetPageProperties(int startRowIndex, int maximumRows, bool databind)

{

int newPageIndex = (startRowIndex / maximumRows);

this.PageSize = maximumRows;

if (this.PageIndex != newPageIndex)

{

bool isCanceled = false;

if (databind)

{

// create the event arguments and raise the event

GridViewPageEventArgs args = new GridViewPageEventArgs(newPageIndex);

this.OnPageIndexChanging(args);

isCanceled = args.Cancel;

newPageIndex = args.NewPageIndex;

}

// if the event wasn't cancelled change the paging values

if (!isCanceled)

{

this.PageIndex = newPageIndex;

if (databind)

this.OnPageIndexChanged(EventArgs.Empty);

}

if (databind)

this.RequiresDataBinding = true;

}

}

/// <summary>

/// IPageableItemContainer's StartRowIndex = PageSize * PageIndex properties

/// </summary>

int IPageableItemContainer.StartRowIndex

{

get { return this.PageSize * this.PageIndex; }

}

/// <summary>

/// IPageableItemContainer's MaximumRows = PageSize property

/// </summary>

int IPageableItemContainer.MaximumRows

{

get { return this.PageSize; }

}

/// <summary>

///

/// </summary>

event EventHandler<PageEventArgs> IPageableItemContainer.TotalRowCountAvailable

{

add { base.Events.AddHandler(DataPagerGridView.EventTotalRowCountAvailable, value); }

remove { base.Events.RemoveHandler(DataPagerGridView.EventTotalRowCountAvailable, value); }

}

/// <summary>

///

/// </summary>

/// <param name="e"></param>

protected virtual void OnTotalRowCountAvailable(PageEventArgs e)

{

EventHandler<PageEventArgs> handler = (EventHandler<PageEventArgs>)base.Events[DataPagerGridView.EventTotalRowCountAvailable];

if (handler != null)

{

handler(this, e);

}

}

}

}