如何使用boost :: property_tree來解析與數組根目錄的JSON

Question

如何使用Boost.PropertyTree從數組作爲根節點從JSON中獲取數據？

[ 
    { 
     "ID": "cc7c3e83-9b94-4fb2-aaa3-9da458c976f7", 
     "Type": "VM" 
    } 
] 

Answer 1

數組元素只是一個名爲 「」 的屬性樹鍵值：

for (auto& array_element : pt) { 
    for (auto& property : array_element.second) { 
     std::cout << property.first << " = " << property.second.get_value<std::string>() << "\n"; 
    } 
} 

打印

ID = cc7c3e83-9b94-4fb2-aaa3-9da458c976f7 
Type = VM 

---

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#include <boost/property_tree/ptree.hpp> 
#include <boost/property_tree/json_parser.hpp> 
#include <iostream> 

using namespace boost::property_tree; 

int main() 
{ 
    std::istringstream iss(R"([ 
    { 
     "ID": "cc7c3e83-9b94-4fb2-aaa3-9da458c976f7", 
     "Type": "VM" 
    } 
    ] 
    )"); 

    ptree pt; 
    json_parser::read_json(iss, pt); 

    for (auto& array_element : pt) { 
     for (auto& property : array_element.second) { 
      std::cout << property.first << " = " << property.second.get_value<std::string>() << "\n"; 
     } 
    } 
}