Question

我在列表视图中使用Datapager进行分页时遇到了一些问题。页面很简单。输入搜索文本。单击搜索按钮。将结果显示在列表视图中。结果显示正常但每次我点击页码我都会收到以下错误：

Server Error in '/' Application.

Failed to load viewstate.  The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.Web.HttpException: Failed to load viewstate.  The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[HttpException (0x80004005): Failed to load viewstate.  The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.]
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +317
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +144
   System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +204
   System.Web.UI.Page.LoadAllState() +464
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1849

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34212

这是我的妆容：

<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Search.aspx.cs" Inherits="ITDB.Views.Employee.Search"%>
<asp:Content ID="Content1" ContentPlaceHolderID="Header" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <br />
    <asp:TextBox ID="SearchText" runat="server"></asp:TextBox>
    <asp:Button ID="cmdSearch" runat="server" Text="Search" OnClick="cmdSearch_Click" />
    <hr />

    <asp:ListView id="SearchList" runat="server"
            DataKeyNames="EmployeeID" 
            ItemType="ITDB.DBContext.Employee"      
            >
            <EmptyDataTemplate>
                There are no entries found for Employee
            </EmptyDataTemplate>
            <LayoutTemplate>                                                       
                <asp:PlaceHolder runat="server" id="itemPlaceholder" />
               <asp:DataPager PageSize="5"  runat="server">
                    <Fields>
                        <asp:NextPreviousPagerField ShowLastPageButton="False" ShowNextPageButton="False" ButtonType="Button" ButtonCssClass="btn" />
                        <asp:NumericPagerField ButtonType="Button"  NumericButtonCssClass="btn" CurrentPageLabelCssClass="btn disabled" NextPreviousButtonCssClass="btn" />
                        <asp:NextPreviousPagerField ShowFirstPageButton="False" ShowPreviousPageButton="False" ButtonType="Button" ButtonCssClass="btn" />
                    </Fields>
                </asp:DataPager>                
            </LayoutTemplate>
            <ItemTemplate>
                <%#: Item.FirstName + " " + Item.LastName%>
                <br />   
            </ItemTemplate>
    </asp:ListView>
</asp:Content>
<asp:Content ID="Content3" ContentPlaceHolderID="AfterForm" runat="server">
</asp:Content>

代码背后：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Entity;
using ITDB.DBContext;

namespace ITDB.Views.Employee
{
    public partial class Search : System.Web.UI.Page
    {
        protected ITDB.DBContext.ITDB_MSSQL_Connection _db = new ITDB.DBContext.ITDB_MSSQL_Connection();

        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void cmdSearch_Click(object sender, EventArgs e)
        {
            String szSearch = SearchText.Text;
            SearchList.DataSource = GetSearchList(szSearch);
            SearchList.DataBind();
        }

        private List<ITDB.DBContext.Employee> GetSearchList(String searchString)
        {
            return (from employee in _db.Employee
                    where employee.FirstName.Contains(searchString) ||
                          employee.LastName.Contains(searchString)
                    orderby employee.LastName
                    select employee
                        ).ToList();
        }

    }
}

我在这里做错了什么？非常感谢您的帮助。

Answer 1

这里有一个很好的答案，因为直到运行时才知道这些字段。

http://blog.yeshere.org/2011/04/using-datapager-in-listview.html

将您的DataPager ID设置为：DataPager1

您应该添加并实现ListView的PagePropertiesChanging事件。来自event参数的PagePropertiesChangingEventArgs将提供所有需要的分页属性（StartRowIndex和MaximumRows），以便您可以将它们提供给DataPager。

如果DataPager放在ListView中，就像你的那样：

protected void ListView1_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e) {
  ListView lv = sender as ListView;
  DataPager pager = lv.FindControl("DataPager1") as DataPager;
  pager.SetPageProperties(e.StartRowIndex, e.MaximumRows, false);
  BindData();  // set DataSource to ListView and call DataBind() of ListView
}

如果在外面：

protected void ListView1_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e) {     
      this.DataPage1.SetPageProperties(e.StartRowIndex, e.MaximumRows, false);
      BindData();  // set DataSource to ListView and call DataBind() of ListView
    }

Asp.net C＃listview paging无法加载viewstate

1 个答案: