Json: I want to create Windows Application in Visual Studio 2015 c++, and i have a problem

[FunnyBilbur]

The problem in comment below:

#pragma once
#include <iostream>
#include <fstream>
#include "json.hpp"
using json = nlohmann::json;
namespace Project1 {
    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
    using namespace System::Windows::Forms;
    using namespace System::Data;
    using namespace System::Drawing;

    /// <summary>
    /// Summary for MyForm
    /// </summary>
    public ref class MyForm : public System::Windows::Forms::Form
    {
    public:
        MyForm(void)
        {
            InitializeComponent();
            //
            //TODO: Add the constructor code here
            //
        }

    protected:
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        ~MyForm()
        {
            if (components)
            {
                delete components;
            }
        }
    public: System::Windows::Forms::Button^  button1;
    public: System::Windows::Forms::TextBox^  textBox1;
    private: System::Windows::Forms::TextBox^  textBox2;
    public:
    protected:

    private:
        /// <summary>
        /// Required designer variable.
        /// </summary>
        System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        void InitializeComponent(void)
        {
            this->button1 = (gcnew System::Windows::Forms::Button());
            this->textBox1 = (gcnew System::Windows::Forms::TextBox());
            this->textBox2 = (gcnew System::Windows::Forms::TextBox());
            this->SuspendLayout();
            // 
            // button1
            // 
            this->button1->Location = System::Drawing::Point(157, 164);
            this->button1->Name = L"button1";
            this->button1->Size = System::Drawing::Size(81, 35);
            this->button1->TabIndex = 0;
            this->button1->Text = L"button1";
            this->button1->UseVisualStyleBackColor = true;
            this->button1->Click += gcnew System::EventHandler(this, &MyForm::button1_Click);
            // 
            // textBox1
            // 
            this->textBox1->Location = System::Drawing::Point(48, 32);
            this->textBox1->Name = L"textBox1";
            this->textBox1->Size = System::Drawing::Size(173, 20);
            this->textBox1->TabIndex = 1;
            this->textBox1->Text = "Hi Dima";
            // 
            // textBox2
            // 
            this->textBox2->Location = System::Drawing::Point(48, 226);
            this->textBox2->Name = L"textBox2";
            this->textBox2->Size = System::Drawing::Size(184, 20);
            this->textBox2->TabIndex = 2;
            // 
            // MyForm
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(284, 262);
            this->Controls->Add(this->textBox2);
            this->Controls->Add(this->textBox1);
            this->Controls->Add(this->button1);
            this->Name = L"MyForm";
            this->Text = L"MyForm";
            this->ResumeLayout(false);
            this->PerformLayout();

        }
#pragma endregion
    private: int TextSave() {
        using namespace std;
        String^ T = textBox1->Text;
        ofstream file;
        file.open("package.json");
        json obj;
        obj["name"] = T; // <--  Error "No operator "=" matches these operands
        file << obj;
        file.close();
        cin.get();
        return 0;


    }
    private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
        TextSave();

    }
    };
}

[szikra]

I'm not familiar with managed C++ but T isn't Platform::String class? Shouldn't that be converted to std::string when trying to assign it to obj["name"]?

something like http://stackoverflow.com/questions/28759212/convert-platformstring-to-stdstring

[ibroheem]

This issue is not related to the library.
The above link @szikra should solve your issue though.

[Problem with Microsoft and its ideologies]

[nlohmann]

I also think this conversion is out of scope of the library. However, you could add a conversion from Platform::String to json by implementing a to_json function which basically does what is described in the StackOverflow article. See https://github.com/nlohmann/json#arbitrary-types-conversions on how to do this.

[nlohmann]

@FunnyBilbur Did this solve your problem?

[FunnyBilbur]

@nlohmann Yes. I'm just convert String^ to string:
void MarshalString(String ^ s, std::string& os) {
using namespace Runtime::InteropServices;
const char* chars =
(const char)(Marshal::StringToHGlobalAnsi(s)).ToPointer();
os = chars;
Marshal::FreeHGlobal(IntPtr((void)chars));
}
private: int TextSave() {
using namespace std;
String^ das = textBox1->Text;
string da;
MarshalString(das, da);
String^ p1 = textBox2->Text;
string p2;
MarshalString(p1, p2);
ofstream file;
file.open("package.json");
json obj;
obj["name"] = da;
obj["name1"]=p2;
obj["name2"]="Dima";
file << obj;
file.close();
cin.get();
return 0;

}

[FunnyBilbur]

@nlohmann But i Have new question. My program writes the data sequentially into one line(package.json). How to fix this?
primary result: {"name":"Dima1997","name1":"Oleg1997","name2":"Dima"}
but i want like this:
{
"name":"Dima1997",
"name1":"Oleg1997",
"name2":"Dima"
}

[nlohmann]

The dump() function has a parameter for indentation, see https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5319dc1bb9dfe19ce7ff559aaded3422.html#a5319dc1bb9dfe19ce7ff559aaded3422

[FunnyBilbur]

@nlohmann thanks. Working. Okay. Then I need convert type string to String^
How to change this method for me?:
void MarshalString(String ^ s, std::string& os) {
using namespace Runtime::InteropServices;
const char* chars =
(const char)(Marshal::StringToHGlobalAnsi(s)).ToPointer();
os = chars;
Marshal::FreeHGlobal(IntPtr((void)chars));
}

[FunnyBilbur]

@nlohmann Nevermind. I'm find the way:
json array;
array["name"] = "Dima";
array["name1"] = "Oleg";
array["name2"] = da; // it's TextBox1
array["name3"] = "Alina";
array["name4"] = "Vika";
string sa = array.at("name2");
String^ s = gcnew String(sa.c_str());
label1->Text = s;

[FunnyBilbur]

@nlohmann Look, i need your help.
private: int TextSave() {
using namespace std;
....
.....
...
ofstream file;
file.open("package.json");
json obj;
obj["PCB1"] = d1;
obj["PCB2"]= d2;
obj["PCB3"] = d3;
obj["PCB4"] = d4;
obj["PCB5"] = d5;
obj["PCB6"] = d6;
file << obj.dump(0)<< "nn";
file << obj;
file.close();
cin.get();
return 0; }

look: I enter this data:
d1= aa
d2 = bb
d3= cc
d4 = dd
d5 = ee
d6 =ff
and in file package.json I have next results:
{
"PCB1": "aa",
"PCB2": "bb",
"PCB3": "aa", //How is possible? In this place must be "cc"
"PCB4": "aa", //
"PCB5": "aa", //
"PCB6": "aa" //
}

[nlohmann]

Hard to tell from the code you show. This depends on the type of d1 ... d6.

[FunnyBilbur]

@nlohmann it's my stupid mistake, because d3-d6 = textBox1->Text ))))))
Thanks

[nlohmann]

Great. I shall close this ticket, as the original issue has been solved. Please feel free to open a new issue in case you encounter another problem.