【发布时间】：2014-10-12 05:42:35
【问题描述】：
我正在尝试在滚动页面时将数据从数据库加载到gridview。它的工作原理是这样的
1) 最初加载页面时，gridview 会从database 中显示 10 个数据（工作正常）
2)在滚动gridview 时显示要加载的图像，然后使用 ajax json 方法调用服务器端函数以从数据库中加载接下来的 5 个数据
3) 成功点击此函数后，javascript 会删除要加载的图像，并在 gridview 中附加下 5 个数据。
现在的问题是删除图像后，gridview 在接下来的 5 次中一次又一次地显示数据库中的第一个数据。请帮忙..
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
newscontainer.DataSource = GetNewsPageWise(1, 10);
newscontainer.DataBind();
}
}
public static DataSet GetNewsPageWise(int pageIndex, int pageSize)
{
string constring = "server=***;uid=***;pwd=******;database=*******";
using (SqlConnection con = new SqlConnection(constring))
{
using (SqlCommand cmd = new SqlCommand("[GetNewsPageWise]"))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@PageIndex", pageIndex);
cmd.Parameters.AddWithValue("@PageSize", pageSize);
cmd.Parameters.Add("@PageCount", SqlDbType.Int, 4).Direction = ParameterDirection.Output;
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataSet ds = new DataSet())
{
sda.Fill(ds, "popnews");
DataTable dt = new DataTable("PageCount");
dt.Columns.Add("PageCount");
dt.Rows.Add();
dt.Rows[0][0] = cmd.Parameters["@PageCount"].Value;
ds.Tables.Add(dt);
return ds;
}
}
}
}
}
[WebMethod]
public static string GetCustomers(int pageIndex)
{
//Added to similate delay so that we see the loader working
//Must be removed when moving to production
System.Threading.Thread.Sleep(2000);
return GetNewsPageWise(pageIndex, 5).GetXml();
}
}
Javascript
<script type="text/javascript">
var pageIndex = 1;
var pageCount;
$(function () {
//Remove the original GridView header
$("[id$=newscontainer] tr").eq(0).remove();
});
//Load GridView Rows when DIV is scrolled
$(window).scroll(function () {
if ($(window).scrollTop() == $(document).height() - $(window).height()) {
GetRecords();
}
});
//Function to make AJAX call to the Web Method
function GetRecords() {
pageIndex++;
if (pageIndex == 2 || pageIndex <= pageCount) {
//Show Loader
if ($("[id$=newscontainer] .loader").length == 0) {
var row = $("[id$=newscontainer] tr").eq(0).clone(true);
row.addClass("loader");
row.children().remove();
row.append('<td colspan = "999" style = "background-color:white"> <asp:Image ID="loader" runat="server" Height="50px" ImageUrl="~/Images/loader.gif" Width="51px" /></td>');
$("[id$=newscontainer]").append(row);
}
$.ajax({
type: "POST",
url: "News.aspx/GetCustomers",
data: '{pageIndex: ' + pageIndex + '}',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: OnSuccess,
failure: function (response) {
alert(response.d);
},
error: function (response) {
alert(response.d);
}
});
}
}
function OnSuccess(response) {
var xmlDoc = $.parseXML(response.d);
var xml = $(xmlDoc);
pageCount = parseInt(xml.find("PageCount").eq(0).find("PageCount").text());
var customers = xml.find("popnews");
$("[id$=newscontainer] .loader").remove();
customers.each(function () {
var customer = $(this);
var row = $("[id$=newscontainer] tr").eq(0).clone(true);
$(".postedon").html(customer.find("newsdate").text());
$(".news").html(customer.find("news").text());
$("[id$=newscontainer]").append(row);
});
//Hide Loader
$("#loader").hide();
}
使用的存储过程
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE [dbo].[GetNewsPageWise]
@PageIndex INT = 1
,@PageSize INT = 10
,@PageCount INT OUTPUT
AS
BEGIN
SET NOCOUNT ON;
SELECT ROW_NUMBER() OVER
(
ORDER BY [newsid] ASC
)AS RowNumber
,[newsid]
,[news]
,[newsdate]
,[newstime]
INTO #Results
FROM [popnews]
DECLARE @RecordCount INT
SELECT @RecordCount = COUNT(*) FROM #Results
SET @PageCount = CEILING(CAST(@RecordCount AS DECIMAL(10, 2)) /
CAST(@PageSize AS DECIMAL(10, 2)))
PRINT @PageCount
SELECT * FROM #Results
WHERE RowNumber BETWEEN(@PageIndex -1) * @PageSize + 1
AND(((@PageIndex -1) * @PageSize + 1) + @PageSize) - 1
DROP TABLE #Results
END
【问题讨论】：
-
我认为问题不在 AJAX 中，尝试将调试点放在 GetNewsPageWise() 中并检查返回的 ds 的内容。
标签： c# javascript asp.net ajax gridview