数据解析（XML，JSON）

XML文件有多种样式，标准的是把数据存在字节点上，还有的就是把数据直接存储在属性里面

#import"ViewController.h"

@interface ViewController ()<NSXMLParserDelegate>{
    NSMutableArray * listArr;
     NSString      *elementTag;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    //1----获取工程中的资源
    NSString * path = [[ NSBundle mainBundle] pathForResource:@"student" ofType:@"xml"];
//    NSLog(@"%@",path);

    //2----获取资源文件保存数据
    NSData * data = [NSData dataWithContentsOfFile:path];
//    NSLog(@"%@",data);

    //3.－－－指定解析对象
    NSXMLParser * parper = [[NSXMLParser alloc] initWithData:data];
    parper.delegate = self;
    NSLog(@"%@",parper);

    //4.-- --开始解析
    [parper parse];
}

//5.----开始解析准备工作---(从头标签开始)
-(void)parserDidStartDocument:(NSXMLParser *)parser{
    //一般在此方法进行数组或字典等对象的初始化
    listArr = [NSMutableArray  array];
}

//6.－－－－－开始解析头标签
-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{
    //elementName 头标签名。attributeDict代表头标签所在<>中用=连接的内容

    elementTag = elementName;
    if ([elementName isEqualToString:@"User"]) {

        NSString * s = [attributeDict objectForKey:@"id"];
        NSMutableDictionary * dict = [NSMutableDictionary dictionary];
        [dict setObject:s forKey:@"id"];
        [listArr addObject:dict];

    }
}

//7.－－－－－－获取标签存储的字符串
-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{

    NSMutableDictionary * dic = [listArr lastObject];
    if ([elementTag isEqualToString:@"name"] || [elementTag isEqualToString:@"age"]) {
        [dic setObject:string forKey:elementTag];
    }
}

//8.-----将elementTag置空
-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
    //解析头标签结束之后，将elementTag置空，避免尾标签对foundCharacters造成的影响
    elementTag = nil;
}

//9.----准备结束解析工作---(在尾标签结束)-(void)parserDidEndDocument:(NSXMLParser *)parser{

for (NSMutableDictionary * dic in listArr) {

NSLog(@"-->%@,%@,%@",[dic objectForKey:@"id"],dic[@"name"],dic[@"age"]);

}}

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JSON解析

1.先取出路径

2.获取资源文件保存数据

3.用系统自带库进行解析－－（致此解析完成）

4.取出：a.先取出最外层的数组或者字典， b，然后一次往里面解析数组或者字典 c. 最后对数组或者字典进行遍历

Weather.h

#import <Foundation/Foundation.h>

@interface Weather : NSObject

@property (nonatomic,copy)NSString * raRadarde;
@property (nonatomic,copy)NSString * SD;
@property (nonatomic,copy)NSString * WD;
@property (nonatomic,copy)NSString * WS;
@property (nonatomic,copy)NSString * WSE;
@property (nonatomic,copy)NSString * city;
@property (nonatomic,copy)NSString * cityid;
@property (nonatomic,copy)NSString * isRadar;
@property (nonatomic,copy)NSString * njd;
@property (nonatomic,copy)NSString * qy;
@property (nonatomic,copy)NSString * temp;
@property (nonatomic,copy)NSString * time;

@end

Weather.m

#import "Weather.h"

@implementation Weather

-(NSString *)description{
return [NSString stringWithFormat:@"%@：%@ ,%@,%@ ,%@,%@,%@：%@ ,%@,%@,%@,%@",_raRadarde,_SD,_WD,_WS,_WSE,_city,_cityid,_isRadar,_njd,_qy,_temp,_time];
}
@end

ViewControl.h

#import "ViewController.h"
#import "Weather.h"
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];


    NSString * str = @"http://www.weather.com.cn/data/sk/101010100.html";
    NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:str]];
//    NSLog(@"%@",data);
    id obj = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
//    NSLog(@"%@",obj);
    NSDictionary *dataDic = [obj objectForKey:@"weatherinfo"];//取出最外层的字典
    NSLog(@"%@",dataDic);
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

//网络数据解析分为两种方式（XML，JSON），其中JSON使我们常用的比较简单的解析方式
//JSON--解析步骤：
//1--先取出文件路径
//2--获取资源数据保存
//3--用系统库自带的方式（NSJSONSerialization）进行解析，（致此解析完成）
//--取出解析结果：a.先取出最外层的数组或者字典，b.然后依次往里面解析数组或者字典 c.最后对需要的数组或者字典进行遍历

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    //获取工程中的资源
    NSString * path = [[NSBundle mainBundle] pathForResource:@"json" ofType:@"json"];
    //将资源文件转换为data数据
    NSData * data = [NSData dataWithContentsOfFile:path];

//用系统自带库进行解析（只能对数据进行解析）

    id obj = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
//    NSLog(@"%@",obj);
    //取出url
    NSArray * arr = [obj objectForKey:@"student"];
    NSLog(@"%@",arr);

    for (NSMutableDictionary * dict in arr) {
//        NSLog(@"%@",dict);
        NSString * str = dict[@"name"];
        NSLog(@"%@",str);
        NSString * str1 = dict[@"age"];
        NSLog(@"%@",str1);
        NSString * str2 = dict[@"scroe"];
        NSLog(@"%@",str2);

//        NSLog(@"-->%@,%@,%@",dict[@"name"],dict[@"age"],dict[@"scroe"]);

    }

}