Dostęp między klasami do vectora

W klasie TMenu pobieram dane za pomocą load_data i pakuje je do zmiennej v. I chciałbym teraz w by w klasie TModification pobierać te elementy v do ComboBox(iteams). I nie wiem jak to zrobić bo poniższy zapis nie działa

TMENU.CPP
TMenu::TMenu(){
InitializeComponent();
v = new vector<string>;
}

vector<string> TMenu::return_v(){
    return v[0];
}

void TMenu::load_data() {
    int numerWiersza = 0;

    string wiersz;
    ifstream f("przystanki.txt");
    if (f.is_open())
    {
        while (getline (f, wiersz,'\t'))
        {                       
            v->push_back(wiersz);                        
        }
    }
    f.close();
}

....
....
/// Wczytywanie danych
System::Void TMenu::TMenu_Load(System::Object^ sender, System::EventArgs^ e){
load_data();
}

TMODIFICATION.h
#include "TMenu.h"
....
....
....
private: System::Void TModification_Load(System::Object ^{sender, System::EventArgs} e) {
cmb_Stop->Items->Add(TMenu::v[0]);
}

Skoro używasz .NET to używaj go razem ze wszystkimi "dobrodziejstwami" łącznie z listami oraz odczytem plików.

a na vector jak mogę to zrobić?

TMenu ^mnu=gcnew TMenu();
mb_Stop->Items->Add(gcnew String(mnu->v[0]));

Z tym że podałeś za mało kodu aby dało się napisać od razu i na 100% poprawnie.

próbowałem już tak.
ale niestety ani zapis
cmb_Stop->Items->Add(tmenu->return_v());
ani
cmb_Stop->Items->Add(gcnew String(tmenu->return_v()));
ani
cmb_Stop->Items->Add(gcnew String(tmenu->return_v().c_str));

Funkcja return_v wygląda tak :

vector<string> TMenu::return_v(){
		return v[0];
	} 

TModification.h

#pragma once
#include <string>
#include "TMenu.h"


namespace Project2 {
	using namespace std; 
	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 TModification
	/// </summary>
	public ref class TModification : public System::Windows::Forms::Form
	{
	public:
		TModification(void)
		{
			InitializeComponent();
			//
			//TODO: Add the constructor code here
			//
		}

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~TModification()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  btn_Add_Line;
	protected: 

	private: System::Windows::Forms::TextBox^  tbx_Name;
	private: System::Windows::Forms::ComboBox^  cmb_Stop;




	private: System::Windows::Forms::ComboBox^  cmb_Type;

	private: System::Windows::Forms::Label^  label1;
	private: System::Windows::Forms::Label^  label2;
	private: System::Windows::Forms::Label^  label3;
	private: System::Windows::Forms::RichTextBox^  rtbx_List_Stop;

	private: System::Windows::Forms::Button^  btn_Add_Stop;
	private: System::Windows::Forms::Button^  btn_Delete_Stop;


	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->btn_Add_Line = (gcnew System::Windows::Forms::Button());
			this->tbx_Name = (gcnew System::Windows::Forms::TextBox());
			this->cmb_Stop = (gcnew System::Windows::Forms::ComboBox());
			this->cmb_Type = (gcnew System::Windows::Forms::ComboBox());
			this->label1 = (gcnew System::Windows::Forms::Label());
			this->label2 = (gcnew System::Windows::Forms::Label());
			this->label3 = (gcnew System::Windows::Forms::Label());
			this->rtbx_List_Stop = (gcnew System::Windows::Forms::RichTextBox());
			this->btn_Add_Stop = (gcnew System::Windows::Forms::Button());
			this->btn_Delete_Stop = (gcnew System::Windows::Forms::Button());
			this->SuspendLayout();
			// 
			// btn_Add_Line
			// 
			this->btn_Add_Line->Location = System::Drawing::Point(342, 52);
			this->btn_Add_Line->Name = L"btn_Add_Line";
			this->btn_Add_Line->Size = System::Drawing::Size(75, 23);
			this->btn_Add_Line->TabIndex = 0;
			this->btn_Add_Line->Text = L"Dodaj Linie ";
			this->btn_Add_Line->UseVisualStyleBackColor = true;
			this->btn_Add_Line->Click += gcnew System::EventHandler(this, &TModification::btn_Add_Line_Click);
			// 
			// tbx_Name
			// 
			this->tbx_Name->Location = System::Drawing::Point(40, 26);
			this->tbx_Name->Name = L"tbx_Name";
			this->tbx_Name->Size = System::Drawing::Size(100, 20);
			this->tbx_Name->TabIndex = 1;
			// 
			// cmb_Stop
			// 
			this->cmb_Stop->FormattingEnabled = true;
			this->cmb_Stop->Location = System::Drawing::Point(37, 156);
			this->cmb_Stop->Name = L"cmb_Stop";
			this->cmb_Stop->Size = System::Drawing::Size(121, 21);
			this->cmb_Stop->TabIndex = 2;
			this->cmb_Stop->SelectedIndexChanged += gcnew System::EventHandler(this, &TModification::comboBox1_SelectedIndexChanged);
			// 
			// cmb_Type
			// 
			this->cmb_Type->FormattingEnabled = true;
			this->cmb_Type->Items->AddRange(gcnew cli::array< System::Object^  >(4) {L"Autobusowy", L"Autobusowy/Tranwajowy", L"Tranwajowy", 
				L"Metro"});
			this->cmb_Type->Location = System::Drawing::Point(40, 81);
			this->cmb_Type->Name = L"cmb_Type";
			this->cmb_Type->Size = System::Drawing::Size(121, 21);
			this->cmb_Type->TabIndex = 3;
			// 
			// label1
			// 
			this->label1->AutoSize = true;
			this->label1->Location = System::Drawing::Point(40, 62);
			this->label1->Name = L"label1";
			this->label1->Size = System::Drawing::Size(25, 13);
			this->label1->TabIndex = 4;
			this->label1->Text = L"Typ";
			// 
			// label2
			// 
			this->label2->AutoSize = true;
			this->label2->Location = System::Drawing::Point(37, 141);
			this->label2->Name = L"label2";
			this->label2->Size = System::Drawing::Size(58, 13);
			this->label2->TabIndex = 5;
			this->label2->Text = L"Przystanki ";
			// 
			// label3
			// 
			this->label3->AutoSize = true;
			this->label3->Location = System::Drawing::Point(43, 7);
			this->label3->Name = L"label3";
			this->label3->Size = System::Drawing::Size(40, 13);
			this->label3->TabIndex = 6;
			this->label3->Text = L"Nazwa";
			// 
			// rtbx_List_Stop
			// 
			this->rtbx_List_Stop->Location = System::Drawing::Point(230, 104);
			this->rtbx_List_Stop->Name = L"rtbx_List_Stop";
			this->rtbx_List_Stop->Size = System::Drawing::Size(173, 136);
			this->rtbx_List_Stop->TabIndex = 7;
			this->rtbx_List_Stop->Text = L"";
			// 
			// btn_Add_Stop
			// 
			this->btn_Add_Stop->Location = System::Drawing::Point(38, 196);
			this->btn_Add_Stop->Name = L"btn_Add_Stop";
			this->btn_Add_Stop->Size = System::Drawing::Size(63, 23);
			this->btn_Add_Stop->TabIndex = 8;
			this->btn_Add_Stop->Text = L"Dodaj";
			this->btn_Add_Stop->UseVisualStyleBackColor = true;
			// 
			// btn_Delete_Stop
			// 
			this->btn_Delete_Stop->Location = System::Drawing::Point(119, 196);
			this->btn_Delete_Stop->Name = L"btn_Delete_Stop";
			this->btn_Delete_Stop->Size = System::Drawing::Size(60, 23);
			this->btn_Delete_Stop->TabIndex = 9;
			this->btn_Delete_Stop->Text = L"Usuń";
			this->btn_Delete_Stop->UseVisualStyleBackColor = true;
			// 
			// TModification
			// 
			this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
			this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
			this->ClientSize = System::Drawing::Size(466, 261);
			this->Controls->Add(this->btn_Delete_Stop);
			this->Controls->Add(this->btn_Add_Stop);
			this->Controls->Add(this->rtbx_List_Stop);
			this->Controls->Add(this->label3);
			this->Controls->Add(this->label2);
			this->Controls->Add(this->label1);
			this->Controls->Add(this->cmb_Type);
			this->Controls->Add(this->cmb_Stop);
			this->Controls->Add(this->tbx_Name);
			this->Controls->Add(this->btn_Add_Line);
			this->Name = L"TModification";
			this->Text = L"TModification";
			this->Load += gcnew System::EventHandler(this, &TModification::TModification_Load);
			this->ResumeLayout(false);
			this->PerformLayout();

		}
#pragma endregion
	private: System::Void comboBox1_SelectedIndexChanged(System::Object^  sender, System::EventArgs^  e) {
			 }
	private: System::Void btn_Add_Line_Click(System::Object^  sender, System::EventArgs^  e) {
				 String^ name  = tbx_Name->Text;
				
			 }
private: System::Void TModification_Load(System::Object^  sender, System::EventArgs^  e) {
			 TMenu^ tmenu = gcnew TMenu;
			 
			 MessageBox::Show(gcnew String(tmenu->return_v().c_str()));
			 //cmb_Stop->Items->Add(TMenu::return_v());
			// TMenu::return_v(); 
			 
			 
		 }
};
}
 

TMenu.h

 #pragma once
#include <string>
#include <fstream>
#include "Str.h"
#include <vector>
#include <iostream>
#include <conio.h>
#include "Nawigacja.h"
#include "TModification.h"
#include <stdio.h> 


namespace Project2 {

	using namespace System;
	using namespace System::ComponentModel;
	using namespace System::Collections;
	using namespace System::Windows::Forms;
	using namespace System::Data;
	using namespace System::Drawing;

	using namespace std;

	/// <summary>
	/// Summary for TMenu
	/// </summary>
	public ref class TMenu : public System::Windows::Forms::Form
	{
	public:
		
		

		TMenu(void);

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~TMenu()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  button1;
	private: System::Windows::Forms::Button^  btn_Search;
	private: System::Windows::Forms::Button^  button2;
	private: vector<string> *v  ;
	protected: 





	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->btn_Search = (gcnew System::Windows::Forms::Button());
			this->button2 = (gcnew System::Windows::Forms::Button());
			this->SuspendLayout();
			// 
			// button1
			// 
			this->button1->Location = System::Drawing::Point(109, 176);
			this->button1->Name = L"button1";
			this->button1->Size = System::Drawing::Size(75, 23);
			this->button1->TabIndex = 0;
			this->button1->Text = L"Zakończ";
			this->button1->UseVisualStyleBackColor = true;
			this->button1->Click += gcnew System::EventHandler(this, &TMenu::button1_Click_1);
			// 
			// btn_Search
			// 
			this->btn_Search->Location = System::Drawing::Point(109, 43);
			this->btn_Search->Name = L"btn_Search";
			this->btn_Search->Size = System::Drawing::Size(75, 23);
			this->btn_Search->TabIndex = 2;
			this->btn_Search->Text = L"Wyszukaj";
			this->btn_Search->UseVisualStyleBackColor = true;
			this->btn_Search->Click += gcnew System::EventHandler(this, &TMenu::button3_Click);
			// 
			// button2
			// 
			this->button2->Location = System::Drawing::Point(126, 111);
			this->button2->Name = L"button2";
			this->button2->Size = System::Drawing::Size(75, 23);
			this->button2->TabIndex = 3;
			this->button2->Text = L"button2";
			this->button2->UseVisualStyleBackColor = true;
			this->button2->Click += gcnew System::EventHandler(this, &TMenu::button2_Click);
			// 
			// TMenu
			// 
			this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
			this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
			this->ClientSize = System::Drawing::Size(284, 261);
			this->Controls->Add(this->button2);
			this->Controls->Add(this->btn_Search);
			this->Controls->Add(this->button1);
			this->Name = L"TMenu";
			this->Text = L"TMenu";
			this->Load += gcnew System::EventHandler(this, &TMenu::TMenu_Load);
			this->ResumeLayout(false);

		}
#pragma endregion
///// Deklaracja MEtod
public: System::Void TMenu_Load(System::Object^  sender, System::EventArgs^  e) ;
private: System::Void button1_Click_1(System::Object^  sender, System::EventArgs^  e);
private: System::Void button3_Click(System::Object^  sender, System::EventArgs^  e) ;				
private: System::Void button2_Click(System::Object^  sender, System::EventArgs^  e) ;
	public: vector<string> return_v();
			 
public: void load_data();			

public: void show_data();		 
};
}

TMenu.cpp

 #include "TMenu.h"
namespace Project2{

	TMenu::TMenu(){
		InitializeComponent();
		v = new vector<string>; 
	}

	vector<string> TMenu::return_v(){
		return v[0];
	}

	void TMenu::load_data() {
		int numerWiersza = 0;

		string wiersz;
		ifstream f("przystanki.txt");
		if (f.is_open())
		{
			while (getline (f, wiersz,'\t'))
			{						
				v->push_back(wiersz); 						
			}
		}
		f.close();
	}

	void TMenu::show_data(){
		int i = 0 ; 

				for (i = 0; i<v->size();i++)
				MessageBox::Show(gcnew String(v->at(i).c_str()));
	}

	

	/// Otwarcie Modification
	System::Void TMenu::button3_Click(System::Object^  sender, System::EventArgs^  e){
		 TModification^ new_Window = gcnew TModification;
				 this->Hide();

				 new_Window->ShowDialog();
				 this->Show();
	}
	/// Pokaż dane
	System::Void TMenu::button2_Click(System::Object^  sender, System::EventArgs^  e){
		show_data();
	}
	/// Close 
	System::Void TMenu::button1_Click_1(System::Object^  sender, System::EventArgs^  e){
		Application::Exit();
	}
	/// Wczytywanie danych
	System::Void TMenu::TMenu_Load(System::Object^  sender, System::EventArgs^  e){
		load_data();
	}

}

Czyli znowu kompletne podstawy podstaw.
1.

string TMenu::return_v(int i) { return v[i]; }

public ref class TMenu;
public ref class TModification : public System::Windows::Forms::Form

        private: TMenu ^mnu;
        TModification(TMenu ^mnu):mnu(mnu)
        {
            InitializeComponent();
        }

TModification^ new_Window = gcnew TModification(this);

MessageBox::Show(gcnew String(mnu->return_v(0).c_str()));

Aczkolwiek prawie na 100% coś pokręcisz zaś za dzień czy dwa znowu będziesz tu smarować z takim samym problemem.
Więc weź jakiś kurs przeczytaj.

przy

 private: TMenu ^mnu; 

wywala błąd :
Error 2 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

 public ref class TModification : public System::Windows::Forms::Form
	{
	private: TMenu ^mnu;
	public:
		TModification(TMenu ^mnu):mnu(mnu)
		{
			InitializeComponent();
			//
			//TODO: Add the constructor code here
			//
		}

	

Bo pominąłeś punkt 2.
Zacznij od czytania podstaw.

ale to co napisałeś dalej nie rozwiązuje tego błędu na którym utknąłem z dodawaniem elementów vectora do ComboBox

 cmb_Stop->Items->Add(gcnew String(mnu->v->at(0).c_str())); 

Ależ rozwiązuje jedynie nie możesz zastosować tylko części tego co podałem, musi być wszystko.

zastosowałem wszystko i nadal jest coś nie tak jestes pewny ?
TModification.h

#pragma once
#include <string>
#include "TMenu.h"


namespace Project2 {
	using namespace std; 
	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 TModification
	/// </summary>


 ref class TMenu;
	public ref class TModification : public System::Windows::Forms::Form
	{
	private: TMenu ^mnu;
	public:
		TModification(TMenu ^mnu):mnu(mnu)
		{
			InitializeComponent();
			//
			//TODO: Add the constructor code here
			//
		}

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~TModification()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  btn_Add_Line;
	protected: 

	private: System::Windows::Forms::TextBox^  tbx_Name;
	private: System::Windows::Forms::ComboBox^  cmb_Stop;




	private: System::Windows::Forms::ComboBox^  cmb_Type;

	private: System::Windows::Forms::Label^  label1;
	private: System::Windows::Forms::Label^  label2;
	private: System::Windows::Forms::Label^  label3;
	private: System::Windows::Forms::RichTextBox^  rtbx_List_Stop;

	private: System::Windows::Forms::Button^  btn_Add_Stop;
	private: System::Windows::Forms::Button^  btn_Delete_Stop;


	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->btn_Add_Line = (gcnew System::Windows::Forms::Button());
			this->tbx_Name = (gcnew System::Windows::Forms::TextBox());
			this->cmb_Stop = (gcnew System::Windows::Forms::ComboBox());
			this->cmb_Type = (gcnew System::Windows::Forms::ComboBox());
			this->label1 = (gcnew System::Windows::Forms::Label());
			this->label2 = (gcnew System::Windows::Forms::Label());
			this->label3 = (gcnew System::Windows::Forms::Label());
			this->rtbx_List_Stop = (gcnew System::Windows::Forms::RichTextBox());
			this->btn_Add_Stop = (gcnew System::Windows::Forms::Button());
			this->btn_Delete_Stop = (gcnew System::Windows::Forms::Button());
			this->SuspendLayout();
			// 
			// btn_Add_Line
			// 
			this->btn_Add_Line->Location = System::Drawing::Point(342, 52);
			this->btn_Add_Line->Name = L"btn_Add_Line";
			this->btn_Add_Line->Size = System::Drawing::Size(75, 23);
			this->btn_Add_Line->TabIndex = 0;
			this->btn_Add_Line->Text = L"Dodaj Linie ";
			this->btn_Add_Line->UseVisualStyleBackColor = true;
			this->btn_Add_Line->Click += gcnew System::EventHandler(this, &TModification::btn_Add_Line_Click);
			// 
			// tbx_Name
			// 
			this->tbx_Name->Location = System::Drawing::Point(40, 26);
			this->tbx_Name->Name = L"tbx_Name";
			this->tbx_Name->Size = System::Drawing::Size(100, 20);
			this->tbx_Name->TabIndex = 1;
			// 
			// cmb_Stop
			// 
			this->cmb_Stop->FormattingEnabled = true;
			this->cmb_Stop->Location = System::Drawing::Point(37, 156);
			this->cmb_Stop->Name = L"cmb_Stop";
			this->cmb_Stop->Size = System::Drawing::Size(121, 21);
			this->cmb_Stop->TabIndex = 2;
			this->cmb_Stop->SelectedIndexChanged += gcnew System::EventHandler(this, &TModification::comboBox1_SelectedIndexChanged);
			// 
			// cmb_Type
			// 
			this->cmb_Type->FormattingEnabled = true;
			this->cmb_Type->Items->AddRange(gcnew cli::array< System::Object^  >(4) {L"Autobusowy", L"Autobusowy/Tranwajowy", L"Tranwajowy", 
				L"Metro"});
			this->cmb_Type->Location = System::Drawing::Point(40, 81);
			this->cmb_Type->Name = L"cmb_Type";
			this->cmb_Type->Size = System::Drawing::Size(121, 21);
			this->cmb_Type->TabIndex = 3;
			// 
			// label1
			// 
			this->label1->AutoSize = true;
			this->label1->Location = System::Drawing::Point(40, 62);
			this->label1->Name = L"label1";
			this->label1->Size = System::Drawing::Size(25, 13);
			this->label1->TabIndex = 4;
			this->label1->Text = L"Typ";
			// 
			// label2
			// 
			this->label2->AutoSize = true;
			this->label2->Location = System::Drawing::Point(37, 141);
			this->label2->Name = L"label2";
			this->label2->Size = System::Drawing::Size(58, 13);
			this->label2->TabIndex = 5;
			this->label2->Text = L"Przystanki ";
			// 
			// label3
			// 
			this->label3->AutoSize = true;
			this->label3->Location = System::Drawing::Point(43, 7);
			this->label3->Name = L"label3";
			this->label3->Size = System::Drawing::Size(40, 13);
			this->label3->TabIndex = 6;
			this->label3->Text = L"Nazwa";
			// 
			// rtbx_List_Stop
			// 
			this->rtbx_List_Stop->Location = System::Drawing::Point(230, 104);
			this->rtbx_List_Stop->Name = L"rtbx_List_Stop";
			this->rtbx_List_Stop->Size = System::Drawing::Size(173, 136);
			this->rtbx_List_Stop->TabIndex = 7;
			this->rtbx_List_Stop->Text = L"";
			// 
			// btn_Add_Stop
			// 
			this->btn_Add_Stop->Location = System::Drawing::Point(38, 196);
			this->btn_Add_Stop->Name = L"btn_Add_Stop";
			this->btn_Add_Stop->Size = System::Drawing::Size(63, 23);
			this->btn_Add_Stop->TabIndex = 8;
			this->btn_Add_Stop->Text = L"Dodaj";
			this->btn_Add_Stop->UseVisualStyleBackColor = true;
			// 
			// btn_Delete_Stop
			// 
			this->btn_Delete_Stop->Location = System::Drawing::Point(119, 196);
			this->btn_Delete_Stop->Name = L"btn_Delete_Stop";
			this->btn_Delete_Stop->Size = System::Drawing::Size(60, 23);
			this->btn_Delete_Stop->TabIndex = 9;
			this->btn_Delete_Stop->Text = L"Usuń";
			this->btn_Delete_Stop->UseVisualStyleBackColor = true;
			// 
			// TModification
			// 
			this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
			this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
			this->ClientSize = System::Drawing::Size(466, 261);
			this->Controls->Add(this->btn_Delete_Stop);
			this->Controls->Add(this->btn_Add_Stop);
			this->Controls->Add(this->rtbx_List_Stop);
			this->Controls->Add(this->label3);
			this->Controls->Add(this->label2);
			this->Controls->Add(this->label1);
			this->Controls->Add(this->cmb_Type);
			this->Controls->Add(this->cmb_Stop);
			this->Controls->Add(this->tbx_Name);
			this->Controls->Add(this->btn_Add_Line);
			this->Name = L"TModification";
			this->Text = L"TModification";
			this->Load += gcnew System::EventHandler(this, &TModification::TModification_Load);
			this->ResumeLayout(false);
			this->PerformLayout();

		}
#pragma endregion
	private: System::Void comboBox1_SelectedIndexChanged(System::Object^  sender, System::EventArgs^  e) {
			 }
	private: System::Void btn_Add_Line_Click(System::Object^  sender, System::EventArgs^  e) {
				 String^ name  = tbx_Name->Text;
				
			 }
private: System::Void TModification_Load(System::Object^  sender, System::EventArgs^  e) {
			 mnu = gcnew TMenu();
			 int i = 0;
			 cmb_Stop->Items->Add(gcnew String(mnu->v->at(0).c_str()));
			
			
			 
		 }
};
}

 

TMenu.h

 
#pragma once
#include <string>
#include <fstream>
#include "Str.h"
#include <vector>
#include <iostream>
#include <conio.h>
#include "Nawigacja.h"
#include "TModification.h"
#include <stdio.h> 


namespace Project2 {

	using namespace System;
	using namespace System::ComponentModel;
	using namespace System::Collections;
	using namespace System::Windows::Forms;
	using namespace System::Data;
	using namespace System::Drawing;

	using namespace std;

	/// <summary>
	/// Summary for TMenu
	/// </summary>
	public ref class TMenu : public System::Windows::Forms::Form
	{
	public:
		
		

		TMenu(void);

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~TMenu()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  button1;
	private: System::Windows::Forms::Button^  btn_Search;
	private: System::Windows::Forms::Button^  button2;
	public: vector<string> *v  ;
	protected: 





	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->btn_Search = (gcnew System::Windows::Forms::Button());
			this->button2 = (gcnew System::Windows::Forms::Button());
			this->SuspendLayout();
			// 
			// button1
			// 
			this->button1->Location = System::Drawing::Point(109, 176);
			this->button1->Name = L"button1";
			this->button1->Size = System::Drawing::Size(75, 23);
			this->button1->TabIndex = 0;
			this->button1->Text = L"Zakończ";
			this->button1->UseVisualStyleBackColor = true;
			this->button1->Click += gcnew System::EventHandler(this, &TMenu::button1_Click_1);
			// 
			// btn_Search
			// 
			this->btn_Search->Location = System::Drawing::Point(109, 43);
			this->btn_Search->Name = L"btn_Search";
			this->btn_Search->Size = System::Drawing::Size(75, 23);
			this->btn_Search->TabIndex = 2;
			this->btn_Search->Text = L"Wyszukaj";
			this->btn_Search->UseVisualStyleBackColor = true;
			this->btn_Search->Click += gcnew System::EventHandler(this, &TMenu::button3_Click);
			// 
			// button2
			// 
			this->button2->Location = System::Drawing::Point(126, 111);
			this->button2->Name = L"button2";
			this->button2->Size = System::Drawing::Size(75, 23);
			this->button2->TabIndex = 3;
			this->button2->Text = L"button2";
			this->button2->UseVisualStyleBackColor = true;
			this->button2->Click += gcnew System::EventHandler(this, &TMenu::button2_Click);
			// 
			// TMenu
			// 
			this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
			this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
			this->ClientSize = System::Drawing::Size(284, 261);
			this->Controls->Add(this->button2);
			this->Controls->Add(this->btn_Search);
			this->Controls->Add(this->button1);
			this->Name = L"TMenu";
			this->Text = L"TMenu";
			this->Load += gcnew System::EventHandler(this, &TMenu::TMenu_Load);
			this->ResumeLayout(false);

		}
#pragma endregion
///// Deklaracja MEtod
public: System::Void TMenu_Load(System::Object^  sender, System::EventArgs^  e) ;
private: System::Void button1_Click_1(System::Object^  sender, System::EventArgs^  e);
private: System::Void button3_Click(System::Object^  sender, System::EventArgs^  e) ;				
private: System::Void button2_Click(System::Object^  sender, System::EventArgs^  e) ;
	public: string return_v(int i) ;
			 
public: void load_data();			

public: void show_data();		 
};
}

TMenu.cpp

 #include "TMenu.h"
namespace Project2{

	TMenu::TMenu(){
		InitializeComponent();
		v = new vector<string>; 
	}

	string TMenu::return_v(int i) { 
		return v[i];
	}

	void TMenu::load_data() {
		int numerWiersza = 0;

		string wiersz;
		ifstream f("przystanki.txt");
		if (f.is_open())
		{
			while (getline (f, wiersz,'\t'))
			{						
				v->push_back(wiersz); 						
			}
		}
		f.close();
	}

	void TMenu::show_data(){
		int i = 0 ; 

				for (i = 0; i<v->size();i++)
				MessageBox::Show(gcnew String(v->at(i).c_str()));
				
	}

	

	/// Otwarcie Modification
	System::Void TMenu::button3_Click(System::Object^  sender, System::EventArgs^  e){
		 TModification^ new_Window = gcnew TModification(this);
				 this->Hide();

				 new_Window->ShowDialog();
				 this->Show();
	}
	/// Pokaż dane
	System::Void TMenu::button2_Click(System::Object^  sender, System::EventArgs^  e){
		show_data();
	}
	/// Close 
	System::Void TMenu::button1_Click_1(System::Object^  sender, System::EventArgs^  e){
		Application::Exit();
	}
	/// Wczytywanie danych
	System::Void TMenu::TMenu_Load(System::Object^  sender, System::EventArgs^  e){
		load_data();
	}

}

No prawie, oprócz tego:

private: System::Void TModification_Load(System::Object^  sender, System::EventArgs^  e) {
             cmb_Stop->Items->Add(gcnew String(mnu->return_v(0).c_str())); 
         }

no niestety nadal coś nie gra :

Zawsze sortuj błędy po numerach.
Pokaż ten TModificvation.h z zaznaczonym 28-ym wierszem

ref class TMenu;
	public ref class TModification : public System::Windows::Forms::Form
	{
	private: TMenu ^mnu;
	public:
		TModification(TMenu ^mnu):mnu(mnu)
		{
			InitializeComponent();
		 	 mnu = gcnew TMenu();                //// 28 linia
			//
			//TODO: Add the constructor code here
			//
		} 

Jak piszesz pod .NET-a to nie używaj string ani vector ani ifstream, tylko klas z .NET-a:

// vector<string> *v;

List<String^> ^v;
...
v = gcnew List<String^>();

Mieszając STL z .NET-em stwarzasz sobie problemy z którymi na każdym kroku musisz bohatersko walczyć.

Musisz ciało konstruktora przenieść do TModification.cpp
Lub przenieś ten wiersz: #include "TModification.h" z TMenu.h do TMenu.cpp

dzięki wielkie działa. Ale jedna rzecz ciekawa się stała. Mianowicie Gdy chcę wyświetlić formę, czyli TModification(Design) to ... nie wyświetla mi się ta forma tylko forma z TMenu.... i nie mogę się dostać do tej prawidłowej..

Przenieś wiersz #include "TModification.h" z TMenu.h do TMenu.cpp