我想做一个翻页类
文件:default.aspx, default.asp.cs ,show_page.cs
命名空间:
guestbook._default
show_page
show_page.cs文件内容using System;
using System.Data;
using System.Data.OleDb;
using System.Web.UI.WebControls;
using System.Web;
namespace show_page
{
/// <summary>
/// show_page 的摘要说明。
/// </summary>
public class show_page
{
System.Web.UI.WebControls.Label lblCurrentPage;
System.Web.UI.WebControls.HyperLink lnkPrev;
System.Web.UI.WebControls.HyperLink lnkNext;
public show_page()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
public PagedDataSource show_page_1(int pages,int PageSize,DataView dv)
{
System.Web.UI.WebControls.PagedDataSource objPds = new System.Web.UI.WebControls.PagedDataSource();
objPds.DataSource = dv;
objPds.AllowPaging = true;
objPds.PageSize = PageSize;
int CurPage;
if (pages > 1)
CurPage=Convert.ToInt32(pages);
else
CurPage=1; objPds.CurrentPageIndex = CurPage-1; lblCurrentPage.Text = "当前页:" + CurPage.ToString();//出错:未将对象引用设置到对象的实例(前面不是定义的吗?web控件在default.aspx)
if (!objPds.IsFirstPage)
lnkPrev.NavigateUrl=HttpContext.Current.Request.Url.PathAndQuery + "?Page=" + Convert.ToString(CurPage-1); if (!objPds.IsLastPage)
lnkNext.NavigateUrl=HttpContext.Current.Request.Url.PathAndQuery+ "?Page=" + Convert.ToString(CurPage+1);
return objPds;
} }
}
异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误:
行 35: objPds.CurrentPageIndex = CurPage-1;
行 36:
行 37: lblCurrentPage.Text = "当前页:" + CurPage.ToString();
行 38: //HttpRequest hr=new HttpRequest.httpR
行 39: if (!objPds.IsFirstPage)
文件:default.aspx, default.asp.cs ,show_page.cs
命名空间:
guestbook._default
show_page
show_page.cs文件内容using System;
using System.Data;
using System.Data.OleDb;
using System.Web.UI.WebControls;
using System.Web;
namespace show_page
{
/// <summary>
/// show_page 的摘要说明。
/// </summary>
public class show_page
{
System.Web.UI.WebControls.Label lblCurrentPage;
System.Web.UI.WebControls.HyperLink lnkPrev;
System.Web.UI.WebControls.HyperLink lnkNext;
public show_page()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
public PagedDataSource show_page_1(int pages,int PageSize,DataView dv)
{
System.Web.UI.WebControls.PagedDataSource objPds = new System.Web.UI.WebControls.PagedDataSource();
objPds.DataSource = dv;
objPds.AllowPaging = true;
objPds.PageSize = PageSize;
int CurPage;
if (pages > 1)
CurPage=Convert.ToInt32(pages);
else
CurPage=1; objPds.CurrentPageIndex = CurPage-1; lblCurrentPage.Text = "当前页:" + CurPage.ToString();//出错:未将对象引用设置到对象的实例(前面不是定义的吗?web控件在default.aspx)
if (!objPds.IsFirstPage)
lnkPrev.NavigateUrl=HttpContext.Current.Request.Url.PathAndQuery + "?Page=" + Convert.ToString(CurPage-1); if (!objPds.IsLastPage)
lnkNext.NavigateUrl=HttpContext.Current.Request.Url.PathAndQuery+ "?Page=" + Convert.ToString(CurPage+1);
return objPds;
} }
}
异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误:
行 35: objPds.CurrentPageIndex = CurPage-1;
行 36:
行 37: lblCurrentPage.Text = "当前页:" + CurPage.ToString();
行 38: //HttpRequest hr=new HttpRequest.httpR
行 39: if (!objPds.IsFirstPage)
文件default.aspx :
<%@ Page language="c#" Codebehind="default.aspx.cs" AutoEventWireup="false" Inherits="atonGuestBook._default" %> <span runat="server">
<asp:label ID="lblCurrentPage" runat="server"></asp:label>
<asp:HyperLink id="lnkPrev" runat="server">上一页</asp:HyperLink>
<asp:HyperLink id="lnkNext" runat="server">下一页</asp:HyperLink></span>
是不是所在空间不同出错.
因为lblCurrentPage._default在guestbook命名空间中,而现在要在show_page.show_page中进行操作.