xmlTextTextReaderNodeType来读取XML元素的类型

参考：http://justcoding.iteye.com/blog/1474176

/**  
 * xmlReaderTypes:  
 *  
 * Predefined constants for the different types of nodes.  
 */    
typedef enum {    
    XML_READER_TYPE_NONE = 0,    
    XML_READER_TYPE_ELEMENT = 1,    
    XML_READER_TYPE_ATTRIBUTE = 2,    
    XML_READER_TYPE_TEXT = 3,    
    XML_READER_TYPE_CDATA = 4,    
    XML_READER_TYPE_ENTITY_REFERENCE = 5,    
    XML_READER_TYPE_ENTITY = 6,    
    XML_READER_TYPE_PROCESSING_INSTRUCTION = 7,    
    XML_READER_TYPE_COMMENT = 8,    
    XML_READER_TYPE_DOCUMENT = 9,    
    XML_READER_TYPE_DOCUMENT_TYPE = 10,    
    XML_READER_TYPE_DOCUMENT_FRAGMENT = 11,    
    XML_READER_TYPE_NOTATION = 12,    
    XML_READER_TYPE_WHITESPACE = 13,    
    XML_READER_TYPE_SIGNIFICANT_WHITESPACE = 14,    
    XML_READER_TYPE_END_ELEMENT = 15,    
    XML_READER_TYPE_END_ENTITY = 16,    
    XML_READER_TYPE_XML_DECLARATION = 17    
} xmlReaderTypes;