如何根据用户选择在 ASPX 中显示 XML 数据？

Question

我有下面给出的 XML。 在此 XML 中，在包含数据的 ASCX 控件的 ASPX 页面中，我想要顶部有一个包含选项“GMAT”、“GRE”、“LSAT”和“MCAT”的下拉列表。 当我选择下面的 GMAT 时，它只会显示 GMAT 手册，与其他手册相同。

您能为此提供一些代码吗？

<?xml version="1.0" encoding="utf-8"?>
<root>
    <data>
        <ImageId>tcm556662</ImageId>
        <ImageURL>/Images/2008_gmat_brochure_uk_thumb_tcm55-7311.gif</ImageURL>
        <ImageTitle>GMAT Brochure</ImageTitle>
        <Description>&lt;p xmlns="http://www.w3.org/1999/xhtml"&gt;Classroom
                     and Online Coursegrams.&lt;/p&gt;</Description>
        <FilePath>/Images/gmat_brochure_uk_tcm55-8064.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5510981</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>GMAT Problem Solving Questions and Answers</ImageTitle>
        <Description>Download Kaplan's GMAT Problem So to each question.</Description>
        <FilePath>/Images/gmat-sample-questions_tcm55-10979.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511066</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>GMAT Sentence Correction Practice Questions</ImageTitle>
        <Description>&lt;p xmlns="http://www.w3.org/1999/xhtml"&gt;Tick the box to
                     download GMsee how you might do on this section of the GMAT
                     exam.&lt;/p&gt;</Description>
        <FilePath>/Images/gmat-sentence-correction_tcm55-11065.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm556663</ImageId>
        <ImageURL>/Images/gre_brochure_thumb_tcm55-7315.gif</ImageURL>
        <ImageTitle>GRE Brochure</ImageTitle>
        <Description>&lt;p xmlns="http://www.w3.org/1999/xhtml"&gt;Courses and
                     Tutoring for the Grprograms&lt;/p&gt;</Description>
        <FilePath>/Images/gre-brochure_tcm55-8065.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511219</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>GRE Quantitative Questions Answers and Explanations</ImageTitle>
        <Description>Download the answers and exp with the correct answer. Tick
                    the box and click download now to start the process.</Description>
        <FilePath>/Images/gre-quantitative-practice-questions_tcm55-11214.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511220</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>GRE Sentence Completion Practice Question Answers and Explanations</ImageTitle>
        <Description>&lt;p xmlns="http://www.w3.org/1999/xhtml"&gt;Complete the
                    sentence on the download now button to see how you did.&lt;/p&gt;</Description>
        <FilePath>/Images/gre-sentence-completions_tcm55-11213.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm558073</ImageId>
        <ImageURL>/Images/lsat_brochure_thumb_tcm55-7316.gif</ImageURL>
        <ImageTitle>LSAT Brochure</ImageTitle>
        <Description>Courses and Tutoring for the Law School Admission US law schools</Description>
        <FilePath>/Images/lsat-brochure_tcm55-8066.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511275</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>LSAT Comparative Reading Practice Questions Answers and Explanations</ImageTitle>
        <Description>Try answering the LSAT Comparative Reading and click on
                     download now.</Description>
        <FilePath>/Images/comparative-reasoning_tcm55-11269.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511281</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>LSAT Reading Comprehension Practice Questions Answers and Explanations</ImageTitle>
        <Description>&lt;p xmlns="http://www.w3.org/1999/xhtml"&gt;Read the passage
                     and try the questions as now Lion Practice Questions Answers
                     and Explanations.&lt;/p&gt;</Description>
        <FilePath>/Images/lsat-reading-comprehension_tcm55-11280.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm558074</ImageId>
        <ImageURL>/Images/mcat_brochure_thumb_tcm55-7317.gif</ImageURL>
        <ImageTitle>MCAT Brochure</ImageTitle>
        <Description>Courses and Tutoring for the Medical College Admission Test
                     (MCAT)</Description>
        <FilePath>/Images/mcat-brochure_tcm55-8067.pdf</FilePath>
    </data>
    <data>
        <ImageId>tcm5511278</ImageId>
        <ImageURL>/Images/practice-test-image_tcm55-10980.JPG</ImageURL>
        <ImageTitle>MCAT Biological Sciences Practice Questions Answers and Explanations</ImageTitle>
        <Description>Have you wri download now to find out how you've done.</Description>
        <FilePath>/Images/mcat-biological-sciences_tcm55-11271.pdf</FilePath>
    </data>
</root>

下面是读取XML文件的函数：

private DataSet GenerateDatasetFromXml()
    {
        string xmlFile = string.Empty;
        DataSet xmlFileData = new DataSet();
        string selItem = string.Empty;
        xmlFile = @Server.MapPath("~/" + ConfigurationManager.AppSettings["BrochureXml"].ToString());
        string sfinalString = "";
        hdnIds.Value = "";
        try
        {
            if (File.Exists(xmlFile))
            {
                xmlFileData.ReadXml(xmlFile);
            }
        }
        catch (Exception ex)
        {
            throw ex;
        } 
        return xmlFileData; 
    }

Answer 1

我想要顶部有一个包含选项“GMAT”、“GRE”、“LSAT”、“MCAT”的下拉菜单

现在，您只能根据字符串解析 ImageTitle 并在其中查找子字符串来选择这些项目 - 不太理想。 。

如果有任何机会，我建议向您的数据添加一个标签（或任何您想要的名称），如下所示：

<data>
  <ImageId>tcm556662</ImageId>
  <ImageURL>/Images/2008_gmat_brochure_uk_thumb_tcm55-7311.gif</ImageURL>
  <ImageTitle>GMAT Brochure</ImageTitle>
  <Type>GMAT</Type>
  <Description><p xmlns="http://www.w3.org/1999/xhtml">Classroom and Online Coursegrams.</p></Description>
  <FilePath>/Images/gmat_brochure_uk_tcm55-8064.pdf</FilePath>
</data>

这样，选择正确的元素就像一个非常简单的 XPath 表达式一样简单：

XmlNodeList _list = myXmlDocument.SelectNodes("//data[Type = 'GMAT']);

一次 您已将数据文件加载到 XmlDocument 中（或者使用 Linq-to-XML 方式，如果您愿意的话）。

马克

Answer 2

如果您有可用的 LINQ，您可以执行以下操作...我不确定 ImageTitle 元素是否是您的匹配元素，但是...

XDocument xml = XDocument.Load("MyXMLFile.xml");

string selectedItem = "GMAT"; //Wherever you get this string from

var matchedItems = xml.Root.Descendants("data")
                           .Where(ele => ele.Element("ImageTitle").Value.StartsWith(selectedItem));

Answer 3

查看那里的 XML 结构，无需以最简单的方式进行格式化即可开箱即用地执行此操作。

如果您有能力更改结构，我会添加一个“”或类似的节点，甚至可能在元素上添加一个属性。 在那里，您可以对每个项目进行分组，提供您想要的价值。

然后，使用 XML 操作方法，您可以轻松地使用 XPath 从列表中选择项目，或创建可用项目的列表。