使用c#解析XML数据

时间:2012-01-23 17:31:41

标签: c# xml parsing xmlreader

我一直在使用c#中的XMLReaderClass挣扎一段时间,似乎无法获得这个概念。基本上我想循环遍历XML文件,如果xml doc中的类别与我传递的类别相同,我想将其名称添加到List中。

这是xml

<?xml version="1.0" encoding="utf-8" ?>
<!-- Do not modify this xml file. -->
<Products>
    <product category="Food"  name="Baking potatoes" />
    <product category="Food" name="Chicken fillet" />
    <product category="Food" name="Chocolate gateau" />
    <product category="Food" name="Madras curry sauce" />
    <product category="Food" name="Organic carrots" />
    <product category="Food" name="Semi-skimmed milk" />
    <product category="Home" name="Washing powder" />
    <product category="Home" name="Rubber gloves" />
    <product category="Home" name="Spray wax" />
    <product category="Home" name="Dish soap" />
    <product category="Pet" name="Cat food" />
    <product category="Pet" name="Dog food" />
    <product category="Pet" name="Collar" />
    <product category="Pet" name="Leash" />
</Products>

这是我的代码,我已经开始研究,但没有走得太远:(

public ReadOnlyCollection<string> GetProductsByCategory(string category)
    {
        List<string> returnList = new List<string>();

        using (XmlReader productsReader = GetProductsReader())
        {


            productsReader.MoveToContent();
            while (productsReader.Read())

                if(productsReader.NodeType == XmlNodeType.Element)
            {
                if (productsReader)
                {
                    if productsReader
                }
            }

        }

        return new ReadOnlyCollection<string>(returnList);
    }

4 个答案:

答案 0 :(得分:1)

在这里使用XmlReader只会是一种痛苦。使用该API使用LINQ to XML,它将使您的生活更轻松。

public static ReadOnlyCollection<string> GetProductsByCategory(string category)
{
    using (var reader = GetProductsReader())
    {
        var doc = XDocument.Load(reader);
        var results = doc.Element("Products")
            .Elements("product")
            .Where(e => (string)e.Attribute("category") == category)
            .Select(e => (string)e.Attribute("name"))
            .ToList();
        return new ReadOnlyCollection<string>(results);
    }
}

如果由于某种原因您仍然希望使用XmlReader,您可以这样阅读:

public static ReadOnlyCollection<string> GetProductsByCategory(string category)
{
    var results = new List<string>();
    var settings = new XmlReaderSettings
    {
        IgnoreWhitespace = true,
        IgnoreComments = true,
    };
    using (var reader = XmlReader.Create(GetProductsReader(), settings))
    {
        reader.MoveToContent();
        reader.ReadStartElement("Products");
        do
        {
            if (reader.IsStartElement("product"))
            {
                if (reader.MoveToFirstAttribute())
                {
                    string currentCategory = null;
                    string currentName = null;
                    do
                    {
                        switch (reader.Name)
                        {
                        case "category":
                            currentCategory = reader.ReadContentAsString();
                            break;
                        case "name":
                            currentName = reader.ReadContentAsString();
                            break;
                        }
                    } while (reader.MoveToNextAttribute());
                    if (currentCategory == category && currentName != null)
                        results.Add(currentName);
                }
            }
        } while (reader.ReadToNextSibling("product"));
    }
    return new ReadOnlyCollection<string>(results);
}

答案 1 :(得分:1)

对于超大型XML文件,使用XmlReader扫描文档比使用XmlDocumentXDocument更有效,这需要将整个文件加载到内存中。访问XmlReader.LocalName属性以确定读者所在元素的类型,并调用XmlReader.GetAttribute()方法获取属性的值。

public ReadOnlyCollection<string> GetProductsByCategory(string category)
{
    List<string> products = new List<string>();

    using (XmlReader productsReader = GetProductsReader())
    {
        productsReader.MoveToContent();

        while (productsReader.Read())
        {
            if (productsReader.NodeType == XmlNodeType.Element &&
                productsReader.LocalName == "product" &&
                productsReader.GetAttribute("category") == category)
            {
                products.Add(productsReader.GetAttribute("name"));
            }
        }
    }

    return new ReadOnlyCollection<string>(products);
}

答案 2 :(得分:0)

我会使用LINQ to XMl(XDocument)而不是旧读者。这将使您开始(假设您的xml位于c:\ temp目录中的文件中):

  var doc = XDocument.Load(@"c:\temp\testxml.xml");
  foreach(var element in doc.Elements("Products").Elements())
  {
    Console.WriteLine(element.Attribute("category"));
  }

答案 3 :(得分:0)

查看Linq to XML,这是一个查找特定属性的示例

http://msdn.microsoft.com/en-us/library/bb387041.aspx