我正在将XML文件绑定到转发器，文本框中的每个项目。触发Save操作时，我需要将更改写回XML文件。我的问题是什么是最有效的方法，记住XML文件非常小。
我能想到三个，我不知道哪个最好：
谢谢！
更新了我的XML文件的示例：
<?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>
这是我的班级：
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; }
}
My Links构造函数：
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);
}
答案 0 :(得分：1)
您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，您的DAL传递并接收List<Url>这些对象，并从应用程序的其余部分抽象数据访问（在您的情况下为XML）。
如果您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。
如果您想要一些代码来说明，请告诉我。
编辑：（一些代码）
假设您的元素具有以下属性，那么这将是您的类：
public class Url
{
public int Id {get; set;}
public string DisplayName {get; set;}
public string Url {get; set;}
}
然后你的DAL类看起来像这样：
/// <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
}
}
}
这些是用于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;
所有这一切，你都会这样称呼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
为了避免任何反序列化XML的问题（XML可能非常挑剔它将要解析的内容），我倾向于创建一些（或所有）我想在代码中使用的类并通过Xml.Serialize运行List方法。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
当您遍历转发器中的每个项目时，您可以像这样使用.NET的对象初始化程序：
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});
}
可以在MSDN上找到有关此功能的详细说明：Object and Collection Initializers (C# Programming Guide)
HTH
答案 1 :(得分：0)
使用XmlDocument加载xml，然后浏览它以查找 包含您要更改的值的元素。
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方法保存更改。
xmlDocument.Save（...）;