NSXMLParser读取XML文件并将数据显示到TableView上

关于XML，有两种解析方式，分别是SAX（Simple API for XML，基于事件驱动的解析方式，逐行解析数据，采用协议回调机制）和DOM（Document Object Model ，文档对象模型。解析时需要将XML文件整体读入，并且将XML结构化成树状，使用时再通过树状结构读取相关数据，查找特定节点，然后对节点进行读或写）。苹果官方原生的NSXMLParse类库采用第一种方式，即SAX方式解析XML，它基于事件通知的模式，一边读取文档一边解析数据，不用等待文档全部读入以后再解析，所以如果你正打印解析的数据，而解析过程中间出现了错误，那么在错误节点之间的数据会正常打印，错误后面的数据不会被打印。解析过程由NSXMLParserDelegate协议方法回调。

首先先创建一个xml文件就叫做xml.xml吧：

<?xml version="1.0" encoding="UTF-8"?>
<Root>
    <Student>
        <pid>1</pid>
        <name>Jack</name>
        <sex>Male</sex>
        <age>18</age>
    </Student>
    <Student>
        <pid>2</pid>
        <name>Jodan</name>
        <sex>Male</sex>
        <age>19</age>
    </Student>
    <Student>
        <pid>3</pid>
        <name>Mily</name>
        <sex>Female</sex>
        <age>18</age>
    </Student>
    <Student>
        <pid>4</pid>
        <name>Rena</name>
        <sex>Female</sex>
        <age>20</age>
    </Student>
    <Student>
        <pid>5</pid>
        <name>Amy</name>
        <sex>Female</sex>
        <age>22</age>
    </Student>
    <Student>
        <pid>6</pid>
        <name>Teresa</name>
        <sex>Female</sex>
        <age>20</age>
    </Student>
</Root>

 接首创建一个相对应的M

//Person.h
#import <Foundation/Foundation.h>

@interface Person : NSObject

@property (nonatomic,copy) NSString *pid;
@property (nonatomic,copy) NSString *name;
@property (nonatomic,copy) NSString *sex;
@property (nonatomic,copy) NSString *age;

@end

//Person.m
#import "Person.h"

@implementation Person

@synthesize pid,name,age,sex;
@end

接着添加一个自定义UITableViewCell类就让它叫做CustomTableViewCell.m吧，下一步将用到，代码如下：

//CustomTableViewCell.h
#import <UIKit/UIKit.h>

@interface CustomTableViewCell : UITableViewCell

@property UILabel *lblName;
@property UILabel *lblSex;
@property UILabel *lblAge;


@end


//CustomTableViewCell.m
#import "CustomTableViewCell.h"

@implementation CustomTableViewCell

@synthesize lblAge,lblName,lblSex;

- (void)awakeFromNib {
    // Initialization code
}

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        UILabel *titleOfNameLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 60, 20)];
        titleOfNameLabel.text = @"姓名：";
        UILabel *titleOfAgeLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 40, 60, 20)];
        titleOfAgeLabel.text = @"年龄：";
        
        UILabel *titleOfSexLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 70, 60, 20)];
        titleOfSexLabel.text = @"性别：";
        
        //titleOfNameLabel.backgroundColor = [UIColor blackColor];
        
        [self addSubview:titleOfNameLabel];
        [self addSubview:titleOfAgeLabel];
        [self addSubview:titleOfSexLabel];
        
        lblName = [[UILabel alloc] initWithFrame:CGRectMake(80, 10, 100, 20)];
        lblAge = [[UILabel alloc] initWithFrame:CGRectMake(80, 40, 100, 20)];
        lblSex = [[UILabel alloc] initWithFrame:CGRectMake(80, 70, 100, 20)];
        
        [self addSubview:lblName];
        [self addSubview:lblAge];
        [self addSubview:lblSex];
    }
    return self;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
}

@end

在storyboard内添加一个ViewController并加一个TableView并设置好相应的约束条件后添加一个继承自UIViewController的类估且就叫做XmlToTableViewController，并设置上一步在storyboard添加的ViewController的Customer Class为XmlToTableViewController。 

XmlToTableViewController要实现NSXMLParserDelegate这个接口，并选择相应要实现的方法。

//XmlToTableViewController.h
#import "ViewController.h"
#import "Person.h"

@interface XmlToTableViewController : ViewController

@property (weak, nonatomic) IBOutlet UITableView *tableView;

@property (nonatomic,strong) NSXMLParser *parser;
@property (nonatomic,strong) NSMutableArray *personArray;
@property (nonatomic,copy) NSString *currentElement;
@property (nonatomic,strong) Person *person;

@end


//XmlToTableViewController.m
#import "XmlToTableViewController.h"
#import "CustomTableViewCell.h"

@interface XmlToTableViewController () <UITableViewDataSource,UITableViewDelegate,NSXMLParserDelegate>

@end

@implementation XmlToTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    dispatch_queue_t q1 = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    
    dispatch_async(q1, ^{
        

    });
    
    NSBundle *bundle = [NSBundle mainBundle];
    NSString *path = [bundle pathForResource:@"xml" ofType:@"xml"];
    NSData *data = [NSData dataWithContentsOfFile:path];
    self.parser = [[NSXMLParser alloc] initWithData:data];
    //添加代理
    self.parser.delegate = self;
    self.personArray = [NSMutableArray arrayWithCapacity:5];
    [self.parser parse];
    
    self.tableView.delegate = self;
    self.tableView.dataSource = self;
}



//几个代理方法的实现，是按逻辑上的顺序排列的，但实际调用过程中中间三个可能因为循环等问题乱掉顺序
//开始解析
- (void)parserDidStartDocument:(NSXMLParser *)parser {
    NSLog(@"parserDidStartDocument");
}

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary<NSString *,NSString *> *)attributeDict {
    self.currentElement = elementName;
    if([self.currentElement isEqualToString:@"Student"]) {
        self.person = [[Person alloc] init];
    }
}

//获取节点内容
-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
    if ([self.currentElement isEqualToString:@"pid"]) {
        [self.person setPid:string];
    } else if([self.currentElement isEqualToString:@"name"]) {
        [self.person setName:string];
    } else if([self.currentElement isEqualToString:@"sex"]) {
        [self.person setSex:string];
    } else if([self.currentElement isEqualToString:@"age"]) {
        [self.person setAge:string];
    }
}

//当一个节点读取完成后
-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
    if([elementName isEqualToString:@"Student"]) {
        [self.personArray addObject:self.person];
    }
    self.currentElement = nil;
}

//完成XML文件的读取
-(void)parserDidEndDocument:(NSXMLParser *)parser {
    NSLog(@"parserDidEndDocument");
    NSLog(@"Student's count is %lu",(unsigned long)[self.personArray count]);
    [self.tableView reloadData];
}


//MARK:TABLEVIEW
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [self.personArray count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSString *idenfifier = @"Cell";
    //PersoUITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:idenfifier];
    CustomTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:idenfifier];
    if (cell == nil) {
        //用xib文件先画好
        /*cell = [[[NSBundle mainBundle] loadNibNamed:@"PersonUITableViewCell" owner:nil options:nil] firstObject];
        Person *currentPerson = [self.personArray objectAtIndex:indexPath.row];
        if (currentPerson) {
            cell.lblName.text = currentPerson.name;
            cell.lblAge.text = currentPerson.age;
            cell.lblId.text = currentPerson.pid;
            cell.lblSex.text = currentPerson.sex;
        }*/
        
        cell = [[CustomTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:idenfifier];
        
        [tableView registerClass:[CustomTableViewCell class] forCellReuseIdentifier:idenfifier];
    }
    Person *currentPerson = [self.personArray objectAtIndex:indexPath.row];
    if (currentPerson) {
        cell.lblName.text = currentPerson.name;
        cell.lblAge.text = currentPerson.age;
        cell.lblSex.text = currentPerson.sex;
    }

    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 126;
}

 最终的效果：