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

[DmytriiTsybuliak]

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?

[DmytriiTsybuliak]

@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;

}

[DmytriiTsybuliak]

@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

[DmytriiTsybuliak]

@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));
}

[DmytriiTsybuliak]

@nlohmann Nevermind. I found 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;

[DmytriiTsybuliak]

@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)<< "\n\n";
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.

[DmytriiTsybuliak]

@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.