如何使用转发器项目有效地更新 XML 文件

<?xml version="1.0" encoding="UTF-8"?>
<Link>
<LinkNode>
<Section>New York</Section>
<Header>New York</Header>
<Item>IT/ Phone Support</Item>
<Details>Ext 5.8115</Details>
<ID>0</ID>
<HyperLink>0</HyperLink>
</LinkNode>
<LinkNode>
<Section>New York</Section>
<Header />
<Item>Email</Item>
<Details>info@gld.com</Details>
<ID>1</ID>
<HyperLink>2</HyperLink>
</LinkNode>
</Link>

public class Link
{
    public String Section { get; set; }
    public String Header { get; set; }
    public String Item { get; set; }
    public String Details { get; set; }
    public Int32 ID { get; set; }
    public Int32 Hyperlink { get; set; }
}

 var LinksList = new List<Links>();
 var query = links_xml.Root.Descendants("LinkNode").Select(d => d);
            foreach (var q in query)
            {

                var linklist = new Links((!string.IsNullOrEmpty(q.Element("Header").Value)) ? q.Element("Header").Value : "",
                    (!string.IsNullOrEmpty(q.Element("Item").Value)) ? q.Element("Item").Value : "",
                    (!string.IsNullOrEmpty(q.Element("Details").Value)) ? q.Element("Details").Value : "",
                    (int)q.Element("ID"), (int)q.Element("HyperLink"));
                LinksList.Add(linklist);
            }

还可以创建包含所需属性的类对象。将 XML 的读取和写入放在 DAL 层中。这样，DAL 就会传递并接收这些对象的List<Url>，并从应用程序的其余部分抽象出数据访问（在本例中为 XML）。

如果选择更改数据存储方法（更改为 SQL 等），则只需更改 DAL 方法，其余代码不受影响。

如果您需要一些代码来说明，请告诉我。

编辑：（一些代码）

假设您的元素具有以下属性，这将是您的类：

public class Url
{
     public int Id {get; set;}
     public string DisplayName {get; set;}
     public string Url {get; set;}
}

然后，DAL 类将如下所示：

/// <summary>
/// Handles data access for Url entities
/// </summary>
public static class UrlDAL
{
    /// <summary>
    /// The path where the file resides
    /// </summary>
    const string __FilePath = @"~'App_Data'";
    /// <summary>
    /// The name of the file
    /// </summary>
    const string __FileName = "UrlList.xml";
    /// <summary>
    /// The name of the temporary file. Used to keep a copy of the file if saving the new file fails.
    /// </summary>
    const string __FileNameTemp = "UrlList_TEMP.xml";
    /// <summary>
    /// Retrieves a list of url entity objects
    /// </summary>
    /// <returns></returns>
    internal static List<Url> Retrieve()
    {
        List<Url> urls = null;
        try
        {
            //read xml file
            XDocument data  = XDocument.Load(HttpContext.Current.Server.MapPath(Path.Combine(UrlDAL.__FilePath, UrlDAL..__FileName)));
            //convert to list
            urls = Xml.DeserializeCollection<Url>(data);
        }
        catch (Exception e)
        {
            //perform logging / error handling
        }
        return urls;
    }
    /// <summary>
    /// Saves the list of Url entities 
    /// </summary>
    /// <param name="urls">The list of url objects to save</param>
    internal static void Create(List<Url> urls)
    {
        try
        {
            //convert list into xml document
            XDocument file = Xml.SerializeCollection<Url>(urls);
            //rename the old file so you have a copy of it if saving the new file fails
            File.Copy(Path.Combine(UrlDAL.__FilePath, UrlDAL.__FileName), Path.Combine(UrlDAL.__FilePath, UrlDAL.__FileNameTemp));
            //saving the new file will overwrite the existing file
            file.Save(UrlDAL.__FilePath);
            //delete the old file
            File.Delete(Path.Combine(UrlDAL.__FilePath, UrlDAL.__FileNameTemp));
        }
        catch (Exception e)
        {
            //perform logging / error handling
            //you should also alert yourself of this error so you can manually restore the old file
        }
    }
}

以下是用于 XML 序列化/反序列化的扩展方法：

public static class Xml
{
    /// <summary>
    /// Converts an XDoc into a List<T> of entities
    /// </summary>
    /// <typeparam name="T">Any serializable object</typeparam>
    /// <param name="doc"></param>
    /// <returns></returns>
    public static List<T> DeserializeCollection<T>(XDocument doc)
    {
        if (doc == null)
            return null;
        try
        {
            XmlSerializer serializer = new XmlSerializer(typeof(List<T>));
            XmlReader reader = doc.CreateReader();
            List<T> result = (List<T>)serializer.Deserialize(reader);
            reader.Close();
            return result;
        }
        catch (Exception e)
        {
            //perform logging / error handling
            return null;
        }
    }
    /// <summary>
    /// Converts a List<T> of entities into an XDoc.
    /// </summary>
    /// <typeparam name="T">Any serializable object</typeparam>
    /// <param name="paramList"></param>
    public static XDocument SerializeCollection<T>(List<T> paramList)
    {
        if (paramList == null)
            return null;
        XDocument doc = new XDocument();
        try
        {
            XmlSerializer serializer = new XmlSerializer(paramList.GetType());
            XmlWriter writer = doc.CreateWriter();
            serializer.Serialize(writer, paramList);
            writer.Close();
            return doc;
        }
        catch (Exception e)
        {
            //perform logging / error handling
            return null;
        }
    }
}

不要忘记添加对以下命名空间的引用：

using System.IO;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;

话虽如此，你会这样称呼 DAL：

//to retrieve the list of urls
List<Url> urls = UrlDAL.Retrieve();
//to save the new list of urls to an xml file
List<Url> urls = [BUILD URL ENTITIES FROM REPEATER];
UrlDAL.Create(urls)

编辑：创建 XML 的提示

为了避免反序列化 XML 时出现任何问题（XML 对它将解析的内容可能非常挑剔），我倾向于在代码中创建一些（或全部）我想使用的类，并通过 Xml.Serialize 方法运行 List。然后，我使用在那里创建的 xml 作为创建 XML 文件的起点。

编辑 从转发器创建实例

循环遍历转发器中的每个项时，可以使用 .NET 的对象初始值设定项，如下所示：

List<Links> links = new List<Links>();
foreach (RepeaterItem item in rptLinks.Items)
{
   //find all your controls and their values
   string details = ((TextBox)e.Item.Findcontrol("txtDetails")).Text;
   //do this for each control
   //use object initialization here
   links.Add(new Link {Details = details, [PROPERTY NAME] = [REPEATER ITEM VALUE], etc});
}

有关此功能的良好说明，请参阅MSDN：对象和集合初始值设定项（C# 编程指南）

呵

呵

使用 XmlDocument 加载 xml，然后浏览它以查找包含要更改的值的元素。

System.Xml.XmlDocument xmlDocument = new System.Xml.XmlDocument();
xmlDocument.Load(<filename or stream>);
Now, choose the most suitable method for you to find the elements or
attributes you want to change:
// For example:
XmlNodeList elemList = xmlDocument .GetElementsByTagName("Machine");
for (int i=0; i < elemList.Count; i++)
{
elemList[i].InnerXml = "Whateveryouwant";
}

然后，调用 Save 方法以保存更改。

xmlDocument.Save（...）;