xml文件的读写。

TinyXml实现的是DOM访问模型，因此提供了一系列的类对应XML文件中的各个节点。主要类间的关系如下：

TiXmlBase：其他类的基类，是个抽象类

TiXmlNode：表示一个节点，包含节点的一般方法，如访问子节点、兄弟节点、编辑自身、编辑子节点

TiXmlDocument：表示整个XML文档，不对应其中某个特定的节点。

TiXmlElement：表示元素节点，可以包含子节点和TiXmlAttribute

TiXmlComment：表示注释

TiXmlDeclaration：表示声明

TiXmlText：表示文本节点

TiXmlUnknown：表示未知节点，通常是出错了

TiXmlAttribute：表示一个元素的属性-Xml file read and write.

TinyXml implements the DOM access model, thus providing a series of classes corresponding to each node in the XML file. The relationship between the main classes is as follows:

TiXmlBase: the base class of other classes, is an abstract class

TiXmlNode: represents a node that contains the general method of the node, such as access to a child node, a sibling node, an edit itself, an edit child node

TiXmlDocument: that the entire XML document, does not correspond to a particular node.

TiXmlElement: Indicates an element node that can contain child nodes and TiXmlAttribute

TiXmlComment: Indicates a comment

TiXmlDeclaration: Indicates a statement

TiXmlText: Indicates the text node

TiXmlUnknown: that unknown node, usually wrong

TiXmlAttribute: represents the attributes of an element