Backend Development
XML/RSS Tutorial
Detailed code examples for interpreting and writing XML files
Detailed code examples for interpreting and writing XML files
This article will cover 3 aspects:
1. Accessing XML files
2. XML Document Object Model
3. XML and DataSet
Here we first introduce two objects for operating XML files: XmlTextReader and XmlTextWriter
The object used to open and read Xml files is the XmlTextReader object. The following example opens a sample file sample.xml
XmlTextReader reader = new XmlTextReader("sample.xml");in the same path as the program. Then we can automatically facilitate the XML file through its Read method. Example:
while(reader.Read())
{
//在这里填写对于XML的操作代码
}Let’s look at a more complicated example.
while(reader.Read())
2{
3 switch(reader.NodeType)
4 {
5 case XmlNodeType.Element: //当前节点是一个元素
6 Console.Write("<" + reader.Name);
7 while(reader.MoveToNextAttribute()) //按照顺序读取下一个属性
8 Console.Write(" " + reader.Name + "='" + reader.Value + "'");
9 Console.Write(">");
10 break;
11 case XmlNodeType.DocumentType: //XML文件的类型声明
12 Console.WriteLine(reader.NodeType + "<" + reader.Name + ">" + reader.Value);
13 break;
14 ……
15 }
16 }Starting from line 3, we judge the type of node based on the NodeType attribute, and perform different processing according to different types of nodes.
The following table lists some commonly used node types.
##XmlTextReaderThe value of NodeType | |||||||||||||||||||||||||||||||||||||||
Type | Description | ||||||||||||||||||||||||||||||||||||||
| All | All nodes | ||||||||||||||||||||||||||||||||||||||
| Attribute | ## An attribute|||||||||||||||||||||||||||||||||||||||
| Escape text that would be treated as a markup language (such as HTML) | |||||||||||||||||||||||||||||||||||||||
| ##Comments separated by | |||||||||||||||||||||||||||||||||||||||
| The root node of the XML data tree | |||||||||||||||||||||||||||||||||||||||
| The type declaration of the document, that is, tag | ##Element | ||||||||||||||||||||||||||||||||||||||
An element, usually the actual data in the XML file | EndTag | ||||||||||||||||||||||||||||||||||||||
| The end position of the element | None | ||||||||||||||||||||||||||||||||||||||
| ## is not a node | Text | ||||||||||||||||||||||||||||||||||||||
| Returns the text content of the element | XMLDeclaration | ||||||||||||||||||||||||||||||||||||||
| XML declaration node, for example | 在进行写入XML文件时我们使用的XmlTextWriter类，它是XmlWriter的子类，速度快且不使用缓存，但是同XmlTextReader一样，在写入XML文件时只能向前。 我们假定要写入的XML文件在C盘根目录下： XmlTextWriter writer = new XmlTextWriter("C:\\sample2.xml",null);Copy after login 在这里如果不想把数据写入文件，而只是想在命令窗口显示，则可以把“Console.Out”作为参数传递给构造器，此时应把上述语句改为： XmlTextWriter writer = new XmlTextWriter(Console.Out); Copy after login 下面我们介绍一下写入XML文件数据的一些常用方法：
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