boost:只是遍历ptree的元素 [英] boost : Just iterate over elements of a ptree

问题描述

这应该很简单(我只是在学习增强功能，所以我错过了一些东西)

This should be simple (I'm just learning boost so I'm missing something)

我已经使用json_read读取了一些简单的JSON，现在有了一个ptree.网络上的所有示例均使用ptree.get("entry_name")来获取条目.我只想做些类似的事情:

I have read in some simple JSON using json_read and now have a ptree. All the examples on the web show using ptree.get("entry_name") to obtain an entry. All I want to do is something like:

 ptree pt;
 read_json(ss,pt);

 BOOST_FOREACH(ptree::value_type &v, pt)
 {
   std::cout << v.{entry_name} << v.{value}
 }

即遍历ptree并写出每个名称(即您在pt.get()中输入的名称)及其对应的值.

i.e. loop through the ptree and write out each name (i.e. what you put into pt.get()) and it's corresponding value.

很抱歉，这很简单

罗斯

推荐答案

我正在搜索同一件事，但找不到任何答案.事实证明确实很简单:

I was searching the same thing, and couldn't find the answer anywhere. It turned out to be pretty simple indeed:

ptree pt;
/* load/fill pt */
for(iterator iter = pt.begin(); iter != pt.end(); iter++)
{
  std::cout << iter->first << "," << iter->second.data() << std::endl;
}

iter->first是条目名称，而iter->second.data()是第一级的条目值. (然后，您可以使用iter->second.begin()/end()进行重复以获取更深层次的信息.)

iter->first is the entry name, and iter->second.data() is the entry value of the first level. (You can then re-iterate with iter->second.begin()/end() for deeper levels.)

此外，如果此迭代中的一个这样的节点不是终端节点，并且本身就是ptree，则可以从此迭代器本身将其作为ptree获得: ptree subPt = iter->second.get_child("nodeName");

Further, if one such node in this iteration is not a terminal node and is itself a ptree, you can get that as ptree from this iterator itself : ptree subPt = iter->second.get_child("nodeName");

这篇关于boost:只是遍历ptree的元素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！