使用ObjectDataSource 控件自定义自己的分页(vs2008新控件Listview)

在看贴子http://msdn.microsoft.com/zh-cn/magazine/cc337898.aspx 时,里边有一段话,如下:

请注意：因为 DataPager 完全依赖 ListView 执行实际的数据分页，而 ListView 又依赖 DataSource 控件，所以对于其它数据绑定控件也存在相同的分页限制。例如，对于 SqlDataSource 控件，仅当其设置为 DataSet 模式时分页才能正常工作，这意味着需要将整个结果集加载到内存中才能执行分页。当然，您可以使用自定义 DataSource 控件或使用 ObjectDataSource 控件自定义自己的分页。

就来试一下做一小例子.

1. objectdatasource前端代码如下:

<asp:ListView ID="ListView1" runat="server" DataSourceID="ObjectDataSource1">
<ItemTemplate>
<tr valign="middle" style="height: 20px;">
<td>
<div class="divNewsListInNewsPage aNewsOdcSolutions">
<a href='/news/newsview/apjnews/<%# Eval("ID") %>'>
<div><%# Eval("Title")%></div>
</a>
</div>
</td>
<td style="width: 150px; COLOR: #006096">
<div style="float: right;" mce_style="float: right;"> <%# Eval("PublishDate") %></div>
</td>
</tr>
</ItemTemplate>

<LayoutTemplate>
<table runat="server" style="width: 100%">
<tr runat="server" style="height: 350px;" valign="top">
<td runat="server">
<table ID="itemPlaceholderContainer" runat="server" border="0" style="width: 100%">
<tr ID="itemPlaceholder" runat="server">
</tr>
</table>
</td>
</tr>
<tr runat="server">
<td runat="server" style="text-align: right" mce_style="text-align: right">
<asp:DataPager ID="DataPager1" runat="server" PageSize='<%$AppSettings:NewsPageSize%>'>
<Fields>
<asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="True"
ShowLastPageButton="True" />
</Fields>
</asp:DataPager>
</td>
</tr>
</table>
</LayoutTemplate>

<EmptyDataTemplate>
<table id="Table1" runat="server" style="">
<tr>
<td>
未返回数据。</td>
</tr>
</table>
</EmptyDataTemplate>
</asp:ListView>

<%--MaximumRowsParameterName="maximumRows"--默认值, 其实就是pageSize--%>
<%--StartRowIndexParameterName="startRowIndex"--默认值--%>
<%--EnablePaging以前datagrid有个allowpaging的--%>
<asp:ObjectDataSource ID="ObjectDataSource1" runat="server"
EnablePaging="true"
OldValuesParameterFormatString="original_{0}"
SelectMethod="SelectAllDataForNewsPageing"
SelectCountMethod="SelectCountForContentAllInfo"
TypeName="Namespace.Content">
</asp:ObjectDataSource>

SelectMethod是指向的查数据方法名字;

SelectCountMethod是指向查找所有数据总行数的方法;

TypeName是上边两个方法所在的类的full type name.

selectParameters可以在前端指定或后端代码指定, 如下:

this.ObjectDataSource1.SelectParameters.Clear();
this.ObjectDataSource1.SelectParameters.Add(new Parameter("url", DbType.String, "aaa.aspx"));
this.ObjectDataSource1.SelectParameters.Add(new Parameter("langCode", DbType.String, bp.FrontLanguage));
this.ObjectDataSource1.SelectParameters.Add(new Parameter("codedefault", DbType.String, codedefault));
this.ObjectDataSource1.SelectParameters.Add(new Parameter("maximumRows", DbType.Int32, ConfigurationManager.AppSettings["NewsPageSize"]));
this.ObjectDataSource1.SelectParameters.Add(new Parameter("startRowIndex", DbType.Int32, "1"));

2. SelectMethod和SelectCountMethod的指向的方法代码如下(注意方法的参数和上面的selectParameters)

public int SelectCountForContentAllInfo(string url, string langCode, string codedefault, int maximumRows, int startRowIndex)
{
string filterString = " CT_URL='" + url + "' and LangCode='" + langCode + "' ";
int returnValue = base.SelectCount<ContentAllInfo>(filterString); //base.SelectCount返回数据所有行数
return returnValue;
}

public List<ContentAllInfo> SelectAllDataForNewsPageing(string url, string langCode, string codedefault, int maximumRows, int startRowIndex)
{
List<ContentAllInfo> list = new List<ContentAllInfo>();
string filterString = " CT_URL='" + url + "' and LangCode='" + langCode + "' ";
list = base.SelectData<ContentAllInfo>(maximumRows, startRowIndex + 1, " PublishDate desc ", filterString); //.OrderByDescending(ca => ca.PublishDate).ToList();

//base.SelectData是根据条件, 每页显示行数参数值maximumRows(以前叫pagesize), 从那一行开始startRowIndex
if (list.Count == 0 && langCode.ToLower() != codedefault.ToLower())
{
filterString = " CT_URL='" + url + "' and LangCode='" + codedefault + "' ";
list = base.SelectData<ContentAllInfo>(maximumRows, startRowIndex + 1, " PublishDate desc ", filterString);
}

return list;
}

3. 根据PageSize和startRowIndex查分页数据的存储过程跟一般一样.

ALTER PROCEDURE [dbo].[存储过程名字]
@TableName nvarchar(128),
@MaxRows int,
@StartRow int,
@SortExpression nvarchar(200),
@FilterString nvarchar(2000)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

-- Insert statements for procedure here
-- Only for Debug
-- SET @TableName = 'tblPurchaseOrder'
-- SET @MaxRows = 10
-- SET @StartRow = 1
-- SET @SortExpression = 'OrderDate'

DECLARE @Filter NVARCHAR(2100);
DECLARE @SqlString NVARCHAR(4000);
DECLARE @ParmDefinition NVARCHAR(500);

DECLARE @EndRow int

SET @EndRow = @MaxRows - 1 + @StartRow

IF @FilterString is null or @FilterString = ''
BEGIN
SET @Filter = ''
END
ELSE
BEGIN
SET @Filter = ' WHERE ('+ @FilterString +') '
END

/* Specify the parameter format one time. */
SET @ParmDefinition = N'@StartRowNum int, @EndRowNum int';

SET @SqlString = N'
WITH TempTable AS
(
SELECT *, ROW_NUMBER() OVER (ORDER BY ' + @SortExpression + ') AS RowNum
FROM [' + @TableName + '] ' + @Filter + '
)
SELECT * FROM TempTable
WHERE RowNum BETWEEN @StartRowNum AND @EndRowNum
ORDER BY ' + @SortExpression
PRINT @SqlString

EXECUTE sp_executesql @SqlString
, @ParmDefinition
, @StartRowNum = @StartRow
, @EndRowNum = @EndRow;
END