如何用Boost C++删除所有Book节点下的Price XML子节点？

我是Boost XML parser新手，需要删除示例中每个Book节点下的Price子节点。目前已成功删除所有Book节点的Author子节点，但只能删除一个Book节点的Price子节点，输出显示仅处理了一个Book，请问如何实现删除所有Book节点的Price子节点？

原代码 #

#include <iostream>
#include <boost/foreach.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <boost/property_tree/detail/ptree_utils.hpp>


int main() {
    std::istringstream iss(R"(
<BookData>
   <Book><Author>A1</Author><Name>B1</Name><Config><Price>C1</Price><Model>M1</Model></Config></Book>
   <Book><Author>A2</Author><Name>B2</Name><Config><Price>C2</Price><Model>M2</Model></Config></Book>
   <Book><Author>A(n-1)</Author><Name>B(n-1)</Name><Config><Price>C(n-1)</Price><Model>M3</Model></Config></Book>
   <Book><Author>A(n)</Author><Name>B(n)</Name><Config><Price>C(n)</Price><Model>M4</Model></Config></Book> 
</BookData>
)");

    boost::property_tree::ptree pt;
    read_xml(iss, pt);

    
    for (auto& node : pt.get_child("BookData")) {
        std::cout << "Child node of BookData: " << node.first << std::endl;
        node.second.erase("Author");
        
    }
    
     for (auto& node : pt.get_child("BookData.Book")) {
        std::cout << "Child node of Book: " << node.first << std::endl;
        if(node.first == "Config" ) {
            std::cout << "Erasing Price" << std::endl;
            node.second.erase("Price");
        }  
    }
    
    write_xml(std::cout, pt, boost::property_tree::xml_writer_make_settings<std::string>(' ', 4));
}

原输出结果 #

Child node of BookData: Book
Child node of BookData: Book
Child node of BookData: Book
Child node of BookData: Book
Child node of Book: Name
Child node of Book: Config
Erasing Price
<?xml version="1.0" encoding="utf-8"?>
<BookData>
    
   
   
   
    
    <Book>
        <Name>B1</Name>
        <Config>
            <Model>M1</Model>
        </Config>
    </Book>
    <Book>
        <Name>B2</Name>
        <Config>
            <Price>C2</Price>
            <Model>M2</Model>
        </Config>
    </Book>
    <Book>
        <Name>B(n-1)</Name>
        <Config>
            <Price>C(n-1)</Price>
            <Model>M3</Model>
        </Config>
    </Book>
    <Book>
        <Name>B(n)</Name>
        <Config>
            <Price>C(n)</Price>
            <Model>M4</Model>
        </Config>
    </Book>
</BookData>

核心问题是：pt.get_child("BookData.Book")只会获取第一个Book节点的子节点，无法遍历所有Book。

正确的做法是复用删除Author时的遍历逻辑——先遍历BookData下的所有Book节点，再针对每个Book节点找到Config子节点并删除Price：

修改后的代码：

#include <iostream>
#include <boost/foreach.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <boost/property_tree/detail/ptree_utils.hpp>


int main() {
    std::istringstream iss(R"(
<BookData>
   <Book><Author>A1</Author><Name>B1</Name><Config><Price>C1</Price><Model>M1</Model></Config></Book>
   <Book><Author>A2</Author><Name>B2</Name><Config><Price>C2</Price><Model>M2</Model></Config></Book>
   <Book><Author>A(n-1)</Author><Name>B(n-1)</Name><Config><Price>C(n-1)</Price><Model>M3</Model></Config></Book>
   <Book><Author>A(n)</Author><Name>B(n)</Name><Config><Price>C(n)</Price><Model>M4</Model></Config></Book> 
</BookData>
)");

    boost::property_tree::ptree pt;
    read_xml(iss, pt);

    // 删除所有Book的Author节点
    for (auto& node : pt.get_child("BookData")) {
        std::cout << "Child node of BookData: " << node.first << std::endl;
        node.second.erase("Author");
    }
    
    // 遍历所有Book节点，删除每个Book下Config中的Price
    for (auto& book_node : pt.get_child("BookData")) {
        if (book_node.first == "Book") {
            auto& config_node = book_node.second.get_child("Config");
            std::cout << "Erasing Price from Book" << std::endl;
            config_node.erase("Price");
        }
    }
    
    write_xml(std::cout, pt, boost::property_tree::xml_writer_make_settings<std::string>(' ', 4));
}

修改后运行，所有Book节点下的Price都会被删除，每个Book的Config节点中只会保留Model子节点。

内容的提问来源于stack exchange，提问作者Taylor swift