ASP.NET RSS Toolkit(RSS工具)

还记得以前吗？以前要做页面上写个小组件，调用指定（RSS输出地址的）的内容。最好的办法就是通过XSLT+XML来输出字符 串。让我们还是花了一分钟的时候回忆一下以前的做法吧

曾经的做法：

Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
            Dim CacheKey As String = Url & "-" & Sort
            Dim objCache As System.Web.Caching.Cache = HttpRuntime.Cache
            If objCache.Item(CacheKey) Is Nothing Then
                Dim xpDocument As XPathDocument = New XPathDocument(Url, XmlSpace.Preserve)
                Dim XTran As XslTransform = New XslTransform
                 XTran.Load(Web.HttpRuntime.AppDomainAppPath & "TransForm.xsl") 'TransForm.xsl
                Dim sw As StringWriter = New StringWriter

                Dim xArgList As XsltArgumentList = New XsltArgumentList
                 xArgList.AddParam("Sort", "", Sort)
                 xArgList.AddParam("strlength", "", strLength)
                 XTran.Transform(xpDocument, xArgList, sw)
                 objCache.Insert(CacheKey, sw, Nothing, DateTime.Now.AddMinutes(15), TimeSpan.Zero)
            End If
            MyBase.Text = CType(objCache.Item(CacheKey), StringWriter).ToString

        End Sub

XSLT转换文件

<?xml version="1.0" encoding="gb2312"?>
<xsl:stylesheet
    version="1.0"
     xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
     xmlns="http://www.w3.org/TR/REC-html40"
     xmlns:msxsl="urn:schemas-microsoft-com:xslt"
     xmlns:dc="http://purl.org/dc/elements/1.1/"
     xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
     xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
     xmlns:resuls="urn:StrLength">
<xsl:param name="Sort" select="'10'"></xsl:param>
<xsl:param name="strlength" select="'15'"></xsl:param>
<xsl:template match="//rss">
    <xsl:apply-templates select="channel" />
</xsl:template>

<msxsl:script language="VB" implements-prefix="resuls">
<![CDATA[
     Function GetSubString(byval origStr As String, byval endIndex As Integer) As String
    Dim bytes As Byte() = System.Text.Encoding.GetEncoding("gb2312").GetBytes(origStr)
    If endIndex >= bytes.Length Then
       Return origStr
    End If
    Dim subBytes(endIndex) As Byte
    Array.Copy(bytes, 0, subBytes, 0, endIndex)
    Return System.Text.Encoding.GetEncoding("gb2312").GetString(subBytes) + ""
End Function 'GetSubString

     public function strDate(byval s as string)as string
         return CDate(s).Day.ToString & "日"
     end function
]]>
</msxsl:script>

<xsl:template match="channel">
    <table width="300" border="0" cellspacing="0" cellpadding="0">
        <xsl:for-each select="item">
            <xsl:if test="position() &lt;=$Sort">
            <tr>
                <td width="21"><img src="http://download.pchome.net/allimage/p1.gif"/></td>
                <td><a href="{link}"><xsl:value-of select="resuls:GetSubString(title,$strlength)"/></a>  <xsl:value-of select="resuls:strDate(dc:date)"/></td>
            </tr>
            </xsl:if>
        </xsl:for-each>
    </table>
</xsl:template>
</xsl:stylesheet>

而现在。根据MS的想法。一切只要拖拖控件就能完成我们的所要功能（我一向不喜欢这样，还是自己DIY好）。所以。下面介绍这款小工具：ASP.NET RSS Toolkit
RSS TOOLKIT主要是从服务器上装载RSS输出（XML格式输出），生成数据集，然后填充到DATALIST控件当中。另外它支持数据缓存的功能
目前最新版本：1.0.0.1
新的特性：

•     Added MaxItems property to RssDataSource to limit the number of items returned.
•     Added automatic generation of <link> tags from RssHyperLink control, to light up the RSS
toolbar icon in IE7. For more information please see http://blogs.msdn.com/rssteam/articles/PublishersGuide.aspx
•     Added protected Context property (of type HttpContext) to RssHttpHandlerBase class, to allow access to the
HTTP request while generating a feed.
•     Added generation of LoadChannel(string url) method in RssCodeGenerator so that one strongly typed
channel class can be used to consume different channels.
•     Fixed problem expanding app relative (~/…) links containing query string when generating RSS feeds.

下载地址：点击下载
详细说明：http://weblogs.asp.net/scottgu/archive/2006/02/22/438738.aspx

创建新的页面

为datalist控件创建新的数据源

选择rssDataSource

输入RSS地址（我这里以http://rss.msnbc.msn.com/id/3032091/device/rss/rss.xml)

根据RSS输出的格式，进行绑定

<%@ Register Assembly="RssToolkit" Namespace="RssToolkit" TagPrefix="RssToolkit" %>



<html>

<head runat="server">

    <title>ScottGu Feed</title>

</head>

<body>

    <form id="form1" runat="server">

    <div>

   

        <h2>ScottGu Blog Feed</h2>   

       

        <asp:DataList ID="DataList1" runat="server" CellPadding="4" DataSourceID="RssDataSource1" ForeColor="#333333">

            <ItemTemplate>

                <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%# Eval("link") %>' Text='<%# Eval("title") %>'></asp:HyperLink>

            </ItemTemplate>

        </asp:DataList>

       

        <RssToolkit:rssdatasource id="RssDataSource1" runat="server" url="http://weblogs.asp.net/scottgu/Rss.aspx">

        </RssToolkit:rssdatasource>



    </div>

    </form>

</body>

</html>

OK。现在可以浏览一下效果

晚上出去吃晚饭的时候。走出外面，感觉到夏天的来到。呵。我喜欢夏天的这种感觉。带上好的心情，出去走走。也是一种很好的享受。最后。推荐一首歌：夏天的味道。