XML資料解析(系統方法)，xml資料解析方法

XML資料解析(系統方法)，xml資料解析方法

XML是一種自描述的資料交換格式。是一種非常重要的資料交換 格式,多年來一直用於各種電腦語言中。XML類似HTML,有一對對標籤對,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>

事先已將資料讀取並儲存在data中.
建立一個類,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;

再建立一個類,同樣繼承自NSObject,命名為userParser,實現xml檔案的讀取.

userParser.h

#import <Foundation/Foundation.h>#import "user.h"@interface userParser : NSObject<NSXMLParserDelegate>//儲存資訊的數組@property(nonatomic,retain)NSMutableArray *array;//執行個體@property(nonatomic,retain)user *people;//建立字串儲存資訊@property(nonatomic,copy)NSMutableString *buffer;//讀取xml檔案-(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]];    //設定代理    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);    }}//遇到開始標籤//attributeDict標籤屬性- (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];    }    }//結束標籤- (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字串結合,取出字串中的空格    [_buffer appendString:[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];}

在viewcontroller中,建立userparser的執行個體對象,通過parserWithString方法實現資料解析

 userParser *uparser=[[userParser alloc]init];
    [uparser parserWithString:user];

 

注:將資料解析與介面顯示分開寫有助於減低程式的耦合,同時也符合MVC編程模式.