iOS 上的 NSXMLParser，给定一个 xml 文件，我如何使用它 [英] NSXMLParser on iOS, how do I use it given a xml file

问题描述

我想知道如何使用 NSXML 解析器.所以假设我有一个简单的 xml 文件，其中包含以下元素:

I was wondering how do I use the NSXML parser. so lets say given I have a simple xml file with elements like:

<Today>
<Date>1/1/1000</Date>
<Time>14:15:16</Time>
</Today>

我怎样才能使用 NSXMLParser 来解析 XML 文件(它在本地，顺便说一句，桌面上)，检查每个元素并将它们存储在一个数组中以便以后显示/使用?

How could I use the NSXMLParser to parse the XML File (It's on locally btw, desktop), check through each element and store each of them in an array either to be displayed/used later?

我正在查看一些关于它的文档，但我不知道如何使用解析器我知道有 3 种方法(或更多，如果我错了，请纠正我)可以被覆盖-..etc didStartElement-..etc didEndElement-..etc 找到字符

I was looking through some documentation about it and I have no idea on how to use the parser I know that there are 3 methods (or more, please correct me if I'm wrong) that can be overridden -..etc didStartElement -..etc didEndElement -..etc foundCharacters

推荐答案

最简单的事情就是做这样的事情:

The simplest thing is to do something like this:

NSXMLParser *xmlParser = [[NSXMLParser alloc]initWithData:<yourNSData>];
[xmlParser setDelegate:self];
[xmlParser parse];

注意 setDelegate: 将委托设置为self"，即当前对象.因此，在该对象中，您需要实现您在问题中提到的委托方法.

Notice that setDelegate: is setting the delegate to 'self', meaning the current object. So, in that object you need to implement the delegate methods you mention in the question.

在您的代码中再往下粘贴:

so further down in your code, paste in:

    - (void) parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName 
        namespaceURI:(NSString *)namespaceURI
       qualifiedName:(NSString *)qualifiedName 
         attributes:(NSDictionary *)attributeDict{

       NSLog(@"I just found a start tag for %@",elementName);
       if ([elementName isEqualToString:@"employee"]){
       // then the parser has just seen an <employee> opening tag
       }         
     }

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
NSLog(@"the parser just found this text in a tag:%@",string);
}

等等.等

当您想要将变量设置为某个标签的值之类的操作时，这有点困难，但通常是使用类变量来完成的，例如BOOL inEmployeeTag"，您将其设置为didStartElement: 方法中的 true (YES) 和 didEndElement: 方法中的 false - 然后在 foundCharacters 方法中检查它的值.如果是，则将 var 赋值给 string 的值，否则不赋值.

It's a little harder when you want to do something like set a variable to the value of some tag, but generally it's done using a class variable caleld something like "BOOL inEmployeeTag" which you set to true (YES) in the didStartElement: method and false in the didEndElement: method - and then check for it's value in the foundCharacters method. If it's yes, then you assign the var to the value of string, and if not you don't.

理查德

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