提取信息。从XML到可可 [英] Extracting info. from XML into Cocoa

问题描述

我试图解析XML以提取某些变量的值。这里有一个例子：

I am trying to parse an XML to extract values of certain variables. Here's an example:

<?xml version='1.0'?>
  <Main xmlns='http://www.abc.uk' version='1.0' name='full'>
    <child1 version='2.0'>
    <value1> xyz </value1>
    <userinfo>
       <name> joe </name>
       <pass> joepass </pass>
   </userinfo>
    </child1>
</Root>

问题：
如何提取要显示的xyz值？
如何提取'joe'和'joepass'来显示？

Question: How do I extract the 'xyz' value to display ? How do I extract 'joe' and 'joepass' to display ?

根据我的理解，child1是属性为version的根。 'value1'和'userinfo'都是元素。在Cocoa中，我如何显示这些值？我可以做一个[child elementsForName：@userinfo，它显示所有的值。我需要特别提取'joe'和'joepass'。

From my understanding, child1 is the root with attribute 'version'. 'value1' and 'userinfo' are both elements. In Cocoa, how would I display these values ? I can do a [child elementsForName:@"userinfo" and it displays all the values. I need to specifically extract 'joe' and 'joepass'. Thanks.

推荐答案

如何将'xyz'值提取到
显示？如何提取'joe'和
'joepass'显示？

How do I extract the 'xyz' value to display ? How do I extract 'joe' and 'joepass' to display ?

这假设你在 NSString 中有你的XML：

With something like this. This assumes you have your XML in an NSString:

NSXMLDocument* xmlDoc;
NSError* error = nil;
NSUInteger options = NSXMLNodePreserveWhitespace|NSXMLDocumentTidyXML;
xmlDoc = [[NSXMLDocument alloc] initWithXMLString:xmlString
                                          options:options
                                            error:&error];
if (!error)
{
    NSArray* value1Nodes = [xmlDoc nodesForXPath:@".//Main/value1" error:&error];
    if (!error)
    {
        NSXMLNode* value1node = [value1Nodes objectAtIndex:0];
        NSString* value1 = [value1node stringValue];
        // .. do something with value1
    }

    NSArray* userInfoNodes = [xmlDoc nodesForXPath:@".//Main/userinfo" error:&error];
    if (!error)
    {
        for (NSXMLNode* userInfoNode in userInfoNodes)
        {
            NSXMLNode* nameNode = [[userInfoNode nodesForXPath:@"./name" error:&error] objectAtIndex:0];
            NSXMLNode* passNode = [[userInfoNode nodesForXPath:@"./pass" error:&error] objectAtIndex:0];
            NSString* name = [nameNode stringValue];
            NSString* pass = [passNode stringValue];
            // .. do something with name and pass
    }
}

有关详情，请参阅Apple的树基于XML的编程指南。

See more details in Apple's Tree-Based XML Programming Guide.

根据我的理解，child1是属性为version的
根。
'value1'和'userinfo'都是
元素。

From my understanding, child1 is the root with attribute 'version'. 'value1' and 'userinfo' are both elements.

/ code>是此XML文档中的根节点，不是 child1 。

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