在 NSXMLParser 中解析 xml [英] Parsing xml in NSXMLParser

问题描述

我已经阅读了许多关于如何从 xml 文件中获取文本的示例，但就是不知道如何操作.这是一个示例 xml 文件:

I have read many examples of how to get text out of xml files, but just don't get how to. Here is a sample xml file:

<?xml version="1.0" encoding="UTF-8"?>
<questions>
    <set>
        <question>Question</question>
        <answer>Answer</answer>
    </set>
</questions>

使用-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI，获取值的最简单方法是什么问题 和 Answer?我已经连接了我的解析器委托等等.

Using -(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI, what's the easiest way to get the values Question and Answer? I already have my parser delegate hooked up and all that blah.

推荐答案

实现NSXMLParser需要实现它的delegate方法.

For implementing NSXMLParser you need to implement delegate method of it.

首先以这种方式启动 NSXMLParser.

First of all initiate NSXMLParser in this manner.

- (void)viewDidLoad {

    [super viewDidLoad];

    rssOutputData = [[NSMutableArray alloc]init];

    //declare the object of allocated variable
    NSData *xmlData=[[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:@""]];// URL that given to parse.

    //allocate memory for parser as well as 
    xmlParserObject =[[NSXMLParser alloc]initWithData:xmlData];
    [xmlParserObject setDelegate:self];

    //asking the xmlparser object to beggin with its parsing
    [xmlParserObject parse];

    //releasing the object of NSData as a part of memory management
    [xmlData release];

}
//-------------------------------------------------------------


-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *) namespaceURI qualifiedName:(NSString *)qName
   attributes: (NSDictionary *)attributeDict
{
    if( [elementName isEqualToString:@"question"])
    {

         strquestion = [[NSMutableString alloc] init];

    }
}


//-------------------------------------------------------------


-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
       // init the ad hoc string with the value     
     currentElementValue = [[NSMutableString alloc] initWithString:string];
  } else {
     // append value to the ad hoc string    
    [currentElementValue appendString:string];
  }
  NSLog(@"Processing value for : %@", string);
}


//-------------------------------------------------------------


-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
    if( [elementName isEqualToString:@"question"])
    {
        [strquestion setString:elementName];
    }

 [currentElementValue release];
  currentElementValue = nil;
}

当解析器对象遇到特定元素的结尾时，将上述委托方法发送给其委托.在此方法 didEndElement 中，您将获得 question 的值.

The above delegate method is sent by a parser object to its delegate when it encounters an end of specific element. In this method didEndElement you will get value of question.

这篇关于在 NSXMLParser 中解析 xml的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！