XML是一種自描述的數據交換格式。是一種非常重要的數據交換 格式,多年來一直用於各種計算機語言中。XML類似HTML,有一對對標簽對,格式比HTML嚴謹,一個<>開始,一個</>結尾.
解析的內容為:
<users> <user id="001"> <name>張三</name> <password>123456</password> <nickname>小張</nickname> <description>1111111111</description> </user> <user id="002"> <name>張三</name> <password>2222222</password> <nickname>小四兒</nickname> <description>李四是個好學生</description> </user> <user id="003"> <name>張三</name> <password>88888888</password> <nickname>小五</nickname> <description>1234567890</description> </user> </users>
事先已將數據讀取並存儲在data中.
創建一個類,繼承自NSObject,命名為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;
再創建一個類,同樣繼承自NSObject,命名為userParser,實現xml文件的讀取.
userParser.h
#import <Foundation/Foundation.h> #import "user.h" @interface userParser : NSObject<NSXMLParserDelegate> //存儲信息的數組 @property(nonatomic,retain)NSMutableArray *array; //實例 @property(nonatomic,retain)user *people; //創建字符串保存信息 @property(nonatomic,copy)NSMutableString *buffer; //讀取xml文件 -(void)parserWithString:(NSString *)string; @end
userparser.m
#import "userParser.h" @implementation userParser -(void)parserWithString:(NSString *)string { //使用系統XML解析方法 NSXMLParser *parser=[[NSXMLParser alloc]initWithData:[string dataUsingEncoding:NSUTF8StringEncoding]]; //設置代理 parser.delegate=self; //開始解析 [parser parse]; } #pragma mark ---NSXMLParserDelegate--- //開始解析 - (void)parserDidStartDocument:(NSXMLParser *)parser { NSLog(@"it begin"); } //解析結束 - (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); } } //遇到開始標簽 //attributeDict標簽屬性 - (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]; } } //結束標簽 - (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]; } } //讀取內容 - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { //NSCharacterSet字符串結合,取出字符串中的空格 [_buffer appendString:[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]]; }
在viewcontroller中,創建userparser的實例對象,通過parserWithString方法實現數據解析
userParser *uparser=[[userParser alloc]init];
[uparser parserWithString:user];
注:將數據解析與界面顯示分開寫有助於減低程序的耦合,同時也符合MVC編程模式.