解析XML
本文以解析本地XML為例，網絡獲取到的返回值只需轉換成NSData型，解析是同理
需要解析的xml文件如下，users.xml
<?xml version="1.0" encoding="UTF-8"?><AllUsers> <message>用戶信息</message> <user> <name>芳仔小腳印</name> <age>10</age> <school>JiangSu University</school> </user> <user> <name>毒蟲</name> <age>22</age> <school>NanJing University</school> </user> <user> <name>女神</name> <age>23</age> <school>HongKong University</school> </user></AllUsers>
我們用一個數組來存放，最終數據結構為
( { message = "用戶信息"; }, { age = 10; name = "芳仔小腳印"; school = "JiangSu University"; }, { age = 22; name = "毒蟲"; school = "NanJing University"; }, { age = 23; name = "女神"; school = "HongKong University"; }) 解析步驟
一、聲明代理 NSXMLParserDelegate
二、解析
復制代碼代碼如下:
// 遇到節點message和user時作為一個字典存放
NSArray *keyElements = [[NSArray alloc] initWithObjects:@"message",@"user", nil];
// 需要解析的字段
NSArray *rootElements = [[NSArray alloc] initWithObjects:@"message",@"name",@"age",@"school", nil];
// 獲取xml文件的路徑
NSString *xmlPath = [[NSBundle mainBundle] pathForResource:@"users" ofType:@"xml"];
// 轉化為Data
NSData *data = [[NSData alloc] initWithContentsOfFile:xmlPath];
// 初始化
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:data];
// 代理
xmlParser.delegate = self;
// 開始解析
BOOL flag = [xmlParser parse];
if (flag) {
NSLog(@"解析成功");
}
else{
NSLog(@"解析出錯");
}
中間變量，在.m的interface的中定義
復制代碼代碼如下:
NSString *currentElement;
NSString *currentValue;
NSMutableDictionary *rootDic;
NSMutableArray *finalArray;
代理方法
復制代碼代碼如下:
#pragma - mark 開始解析時
-(void)parserDidStartDocument:(NSXMLParser *)parser
{
// 用數組存儲每一組信息
finalArray = [[NSMutableArray alloc] init];
}
#pragma - mark 發現節點時
-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
for(NSString *key in self.keyElements){
if ([elementName isEqualToString:key]) {
// 關鍵節點開始時，初始化一個字典來存放值
rootDic = nil;
rootDic = [[NSMutableDictionary alloc] initWithCapacity:0];
}
else {
for(NSString *element in self.rootElements){
if ([element isEqualToString:element]) {
currentElement = elementName;
currentValue = [NSString string];
}
}
}
}
}
#pragma - mark 發現節點值時
-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
if (currentElement) {
currentValue = string;
[rootDic setObject:string forKey:currentElement];
}
}
#pragma - mark 結束節點時
-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
if (currentElement) {
[rootDic setObject:currentValue forKey:currentElement];
currentElement = nil;
currentValue = nil;
}
for(NSString *key in self.keyElements){
if ([elementName isEqualToString:key]) {
// 關鍵節點結束時，將字典存放在數組中
if (rootDic) {
[finalArray addObject:rootDic];
}
}
}
}
#pragma - mark 結束解析
-(void)parserDidEndDocument:(NSXMLParser *)parser
{
}
解析完成后，打印出finalArray為
( { message = "/U7528/U6237/U4fe1/U606f"; }, { age = 10; name = "/U82b3/U4ed4/U5c0f/U811a/U5370"; school = "JiangSu University"; }, { age = 22; name = "/U6bd2/U866b"; school = "NanJing University"; }, { age = 23; name = "/U5973/U795e"; school = "HongKong University"; }) 使用SBJson拼接和解析json
1.ios解析json
使用開源json包，項目地址：
http://www.superloopy.io/json-framework/
復制代碼代碼如下:
NSData * responseData = [respones responseData];
NSString * strResponser = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
SBJsonParser * parser = [[SBJsonParser alloc]init];
NSMutableDictionary *dicMessageInfo = [parser objectWithString:strResponser]; // 解析成json解析對象
[parser release];
//發送者
NSString * sender = [dicMessageInfo objectForKey:@"sender"];
2.json嵌套對象解析：
復制代碼代碼如下:
//要上傳的字符串
NSString *dataStr=[[NSString alloc] initWithString:@"{/"cross/":{/"1/":/"true/",/"2/":/"false/",/"3/":/"true/"}}"];
//獲取響應返回字符串
NSData * responseData = [respones responseData];
NSString * strResponser = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
//嵌套解析
SBJsonParser * parser = [[SBJsonParser alloc]init];
NSMutableDictionary *dicMessageInfo = [parser objectWithString:strResponser]; // 解析成json解析對象
NSMutableDictionary * cross = [dicMessageInfo objectForKey:@"cross"];
NSString *cross1= [cross objectForKey:@"1"];
//解析json到各個字符串
//發送者
[parser release];
NSLog(@"cross1: %@",cross1);
3.拼接json字符串
通過使用SBJson中的SBJsonWriter類的方法- (NSString*)stringWithObject:(id)value可以將一個對象中的值格式化為json字符串，符合key/value格式的數據封裝到NSDictionary后可以使用該方法進行格式化，其他數據通過拼接字符串的方式格式化。
在拼接過程中可以使用類NSMutableString的方法：
復制代碼代碼如下:
- (void)appendString:(NSString *)aString;、
- (void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2);
動態添加字符串。
拼接的字符串可通過json在線驗證的方式驗證其格式是否正確，網址為：
http://jsonlint.com/
復制代碼代碼如下:
-(NSString *) getJsonString
{
NSMutableString *json = [NSMutableString stringWithCapacity:128];
NSString *jsonString=nil;
SBJsonWriter *writer = [[SBJsonWriter alloc] init];
[json appendString:@"{/"data/":{"];
[json appendFormat:@"/"%@/":/"%d/",",@"reset",reset];
if(missionStatus!=NULL)
{
jsonString=[writer stringWithObject:status];
if(jsonString!=NULL)
{
[json appendString:@"/"status/":"];
[json appendString:jsonString];
}
}
[json appendString:@"}}"];
return json;
}
4.利用多個NSDictionary，拼接多層嵌套的json字符串，減少因手工拼接忘記加引號導致的json格式錯誤
示例代碼：
復制代碼代碼如下:
NSDictionary *dataDictionary= [NSDictionary dictionaryWithObjectsAndKeys:mac,@"mac",
game,@"game",
devicetoken,@"devicetoken",
device,@"device",
gv,@"gv",
lang,@"lang",
os,@"os",
hardware,@"hardware",
down,@"down",nil];
NSDictionary *parmDictionary= [NSDictionary dictionaryWithObjectsAndKeys:@"getSession",@"act",
dataDictionary,@"data",nil];
NSDictionary *jsonDictionary=[NSDictionary dictionaryWithObjectsAndKeys:pv,@"pv",
parmDictionary,@"param",nil];
SBJsonWriter *writer = [[SBJsonWriter alloc] init];
NSString *jsonString=nil;
jsonString=[writer stringWithObject:jsonDictionary];
NSLog(@"%@",jsonString);
