XML解析之SAX详解

本文属于作者原创 http://www.cnblogs.com/ldnh/

XML解析的五个步骤

• 1、打开文档

• (void)parserDidStartDocument:(NSXMLParser *)parser ;

• 2、开始查找起始标签

• (void)parser:(NSXMLParser )parser didStartElement:(NSString )elementName namespaceURI:(NSString )namespaceURI qualifiedName:(NSString )qName attributes:(NSDictionary *)attributeDict;

• 3、获取标签内容

• (void)parser:(NSXMLParser )parser foundCharacters:(NSString )string

• 4、查找结束标签

• -(void)parser:(NSXMLParser )parser didEndElement:(NSString )elementName namespaceURI:(NSString )namespaceURI qualifiedName:(NSString )qName

• 5、查询文档结束

• (void)parserDidEndDocument:(NSXMLParser *)parser {

解析详细代码

#import "ViewController.h"#import "JKPTrainInfo.h"@interface ViewController ()
    
     @property (nonatomic,strong) NSMutableArray *dataList;@property (nonatomic,strong) UITableView *tableView;//因为下面多次要用，所以要建一个全局变量@property (nonatomic,strong) JKPTrainInfo *currentInfo;@property (nonatomic,strong) NSMutableString *muString;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.//加载视图[self initUI];//加载数据[self loadData];}#pragma mark -getter and setter methods-(NSMutableArray *)dataList{if (!_dataList) {    _dataList = [NSMutableArray array];}return _dataList;}-(UITableView *)tableView{if (!_tableView) {    _tableView = [[UITableView alloc]initWithFrame:self.view.bounds style:UITableViewStylePlain];    _tableView.dataSource = self;}return _tableView;}- (NSMutableString *)muString{if (!_muString) {  _muString = [NSMutableString string];}return _muString;}#pragma mark - UITableView dataSource- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {return self.dataList.count;}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {static NSString * identifiter = @"cellID";UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:identifiter];if (!cell) {    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:identifiter];}JKPTrainInfo *JkpInfo = self.dataList[indexPath.row];cell.textLabel.text = JkpInfo.trainStation;cell.detailTextLabel.text = JkpInfo.arriveTime;return cell;}#pragma mark - NSXMLParserDelegate //1. 打开文件，开始解析-(void)parserDidStartDocument:(NSXMLParser *)parser{NSLog(@"打开文件,开始解析");//每次解析前进行清空操作-防止多次加载重复数据[self.dataList removeAllObjects];}//2. 查找起始标签- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{//    NSLog(@"%@",elementName);//    //    NSLog(@"%@",attributeDict);if ([elementName isEqualToString:@"trainDetailInfo"]) {    self.currentInfo = [[JKPTrainInfo alloc]init];    [self.currentInfo setValuesForKeysWithDictionary:attributeDict];}//清空muString 数据self.muString.string = @"";}//3.获取标签内容- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{//    NSLog(@"%@",string);//防止多次执行获取内容的方法[self.muString appendString:string];}// 4.查找结束标签-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{//    NSLog(@"%@",elementName);if ([elementName isEqualToString:@"trainDetailInfo"]) {    [self.dataList addObject:self.currentInfo];}else if (![elementName isEqualToString:@"dataSet"]&&![elementName isEqualToString:@"diffgr:diffgram"]){  // self.muString是数据内容  [self.currentInfo setValue:self.muString forKey:elementName];}}//5.解析完成-(void)parserDidEndDocument:(NSXMLParser *)parser{NSLog(@"解析完成");//解析完成后刷新数据[self.tableView reloadData];}#pragma mark - event handle methods- (void)loadData{NSString *urlString = @"http://192.168.1.68/train.xml";NSURL *url = [NSURL URLWithString:urlString];NSURLRequest *requst = [NSURLRequest requestWithURL:url];[NSURLConnection sendAsynchronousRequest:requst queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {    //XML解析  NSXMLParser *parser = [[NSXMLParser alloc]initWithData:data];    parser.delegate = self;    [parser parse];  }];}- (void)initUI{[self.view addSubview:self.tableView];}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.}@end