xml是一种自描述的数据交换格式。是一种非常重要的数据交换 格式,多年来一直用于各种计算机语言中。XML类似HTML,有一对对标签对,格式比HTML严谨,一个<>开始,一个</>结尾.
解析的内容为:
<users> <user id="001"> <name>张三</name> <passWord>123456</password> <nickname>小张</nickname> <description>1111111111</description> </user> <user id="002"> <name>张三</name> <password>2222222</password> <nickname>小四儿</nickname> <description>李四是个好学生</description> </user> <user id="003"> <name>张三</name> <password>88888888</password> <nickname>小五</nickname> <description>1234567890</description> </user> </users>
事先已将数据读取并存储在data中.
创建一个类,继承自NSObject,命名为userInfo
@PRoperty(nonatomic,copy)NSString *uID;@property(nonatomic,copy)NSString *name;@property(nonatomic,copy)NSString *password;@property(nonatomic,copy)NSString *nickname;@property(nonatomic,copy)NSString *description;
再创建一个类,同样继承自NSObject,命名为userParser,实现xml文件的读取.
userParser.h
#import <Foundation/Foundation.h>#import "user.h"@interface userParser : NSObject<NSXMLParserDelegate>//存储信息的数组@property(nonatomic,retain)NSMutableArray *array;//实例@property(nonatomic,retain)user *people;//创建字符串保存信息@property(nonatomic,copy)NSMutableString *buffer;//读取xml文件-(void)parserWithString:(NSString *)string;@end
userparser.m
#import "userParser.h"@implementation userParser-(void)parserWithString:(NSString *)string{ //使用系统XML解析方法 NSXMLParser *parser=[[NSXMLParser alloc]initWithData:[string dataUsingEncoding:NSUTF8StringEncoding]]; //设置代理 parser.delegate=self; //开始解析 [parser parse];}#pragma mark ---NSXMLParserDelegate---//开始解析- (void)parserDidStartDocument:(NSXMLParser *)parser{ NSLog(@"it begin");}//解析结束- (void)parserDidEndDocument:(NSXMLParser *)parser{ NSLog(@"it is over"); for (int i=0; i<_array.count; i++) { user *user=_array[i]; NSLog(@"%@,%@,%@,%@,%@",user.uID,user.name,user.password,user.nickname,user.description); }}//遇到开始标签//attributeDict标签属性- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{ if ([elementName isEqualToString:@"users"]) { _array=[[NSMutableArray alloc]init]; } else if ([elementName isEqualToString:@"user"]) { _people=[[user alloc]init]; //<user id="3"> _people.uID=[attributeDict objectForKey:@"id"]; } else if ([elementName isEqualToString:@"name"]) { _buffer=[[NSMutableString alloc]init]; } else if ([elementName isEqualToString:@"password"]) { _buffer=[[NSMutableString alloc]init]; } else if ([elementName isEqualToString:@"nickname"]) { _buffer=[[NSMutableString alloc]init]; } else if ([elementName isEqualToString:@"description"]) { _buffer=[[NSMutableString alloc]init]; } }//结束标签- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{ if ([elementName isEqualToString:@"name"]) { _people.name=_buffer; } else if ([elementName isEqualToString:@"password"]) { _people.password=_buffer; } else if ([elementName isEqualToString:@"nickname"]) { _people.nickname=_buffer; }else if ([elementName isEqualToString:@"description"]) { _people.description=_buffer; } else if ([elementName isEqualToString:@"user"]) { [_array addObject:_people]; }}//读取内容- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ //NSCharacterSet字符串结合,取出字符串中的空格 [_buffer appendString:[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];}
在viewcontroller中,创建userparser的实例对象,通过parserWithString方法实现数据解析
userParser *uparser=[[userParser alloc]init];
[uparser parserWithString:user];
注:将数据解析与界面显示分开写有助于减低程序的耦合,同时也符合MVC编程模式.
新闻热点
疑难解答