Problemas com lógica - volta ao menu inicial de função int main()

1. Problemas com lógica - volta ao menu inicial de função int main()

paulopimenta6
(usa Debian)

Enviado em 17/02/2024 - 17:45h

Olá pessoal,

Comecei a fazer um código de um sistema de cadastro, mas tive problema, pois o mesmo não retorna ao menu principal. Como existe uma interação entre máquina e usuário continuamente preciso limpar o buffer, porém o mesmo parece atrapalhar na hora que eu tento voltar ou executar uma opção após o primeiro cadastro.

Seguem os códigos:
app.cpp:

 #include <iostream>

#include <string>

#include <ncurses.h>

#include <limits>

#include "book.h"



void addBook(int& counter);

void deleteBook(int& counter);

void editBook(int& counter);

void searchBook(int counter);

void viewAllBooks(int counter);

void quit();



const int MAX_BOOKS = 4;

bool flag = true;



void increment(int& counter) { counter++; }

void decrement(int& counter) { counter--; }



bookLib::Book books[MAX_BOOKS];



int main() {

    int counter = 0;

    int ans;



    initscr(); // Inicializa a tela do ncurses

    raw();     // Desabilita buffering de linha

    keypad(stdscr, TRUE); // Habilita leitura de teclas especiais



    while (flag) {

        clear(); // Limpa a tela



        printw("LIBRARY MANAGEMENT SYSTEM\n\n");

        printw("[1]ADD BOOK\n");

        printw("[2]DELETE BOOK\n");

        printw("[3]EDIT BOOK\n");

        printw("[4]SEARCH BOOK\n");

        printw("[5]VIEW ALL BOOKS\n");

        printw("[6]QUIT\n\n");



        printw("ENTER CHOICE: ");

        refresh(); // Atualiza a tela



        scanw("%d", &ans);



        switch (ans) {

        case 1:

            addBook(counter);

            break;

        case 2:

            deleteBook(counter);

            break;

        case 3:

            editBook(counter);

            break;

        case 4:

            searchBook(counter);

            break;

        case 5:

            viewAllBooks(counter);

            break;

        case 6:

            quit();

            break;

        default:

            printw("Invalid option! Try again\n");

            refresh();

        }



        getch(); // Espera por um caractere

    }



    endwin(); // Finaliza a tela do ncurses

    return 0;

}



void addBook(int& counter) {

    std::string isbn, title, author, edition, publication;



    if (counter >= MAX_BOOKS) {

        printw("YOU HAVE REACHED THE MAXIMUM NUMBER OF BOOKS TO BE ADDED!\n\nPress any key to continue . . .");

        getch();

        return;

    }



    printw("ADDING BOOK...\n");

    printw("Enter ISBN: ");

    refresh();



    // Ler o ISBN usando getch()

    char isbnBuffer[20];

    getstr(isbnBuffer);

    isbn = isbnBuffer;



    // Verificar se o ISBN já existe

    for (int i = 0; i < counter; i++) {

        if (books[i].getIsbn() == isbn) {

            printw("ISBN already exists. Please enter a different ISBN.\n");

            getch();

            return;

        }

    }



    printw("Enter Title: ");

    refresh();

    char titleBuffer[100];

    getstr(titleBuffer);

    title = titleBuffer;



    printw("Enter Author: ");

    refresh();

    char authorBuffer[100];

    getstr(authorBuffer);

    author = authorBuffer;



    printw("Enter Edition: ");

    refresh();

    char editionBuffer[100];

    getstr(editionBuffer);

    edition = editionBuffer;



    printw("Enter Publication: ");

    refresh();

    char publicationBuffer[100];

    getstr(publicationBuffer);

    publication = publicationBuffer;



    books[counter].setIsbn(isbn);

    books[counter].setTitle(title);

    books[counter].setAuthor(author);

    books[counter].setEdition(edition);

    books[counter].setPublication(publication);



    increment(counter);

    printw("\nBOOK ADDED SUCCESSFULLY!\n\nPress any key to continue . . .");

    getch();

}



void deleteBook(int& counter) {

    std::string isbn;

    int choice;

    bool bookFound = false;



    if (counter == 0) {

        printw("THERE IS NO BOOK TO DELETE!\n\nPress any key to continue . . .");

        getch();

        return;

    }



    printw("DELETE BOOK\n\n");

    printw("Enter ISBN: ");

    refresh();



    char isbnBuffer[20];

    getstr(isbnBuffer);

    isbn = isbnBuffer;



    for (int i = 0; i < counter; i++) {

        if (books[i].getIsbn() == isbn) {

            printw("\nBOOK FOUND\n\n");

            printw("Do you want to delete?\n[1] Yes\n[2] No\n\nEnter Choice: ");

            refresh();

            std::cin >> choice;



            if (choice == 1) {

                for (int a = i; a < counter - 1; a++) {

                    books[a] = books[a + 1];

                }

                counter--;

                books[counter].setIsbn("");

                books[counter].setTitle("");

                books[counter].setAuthor("");

                books[counter].setEdition("");

                books[counter].setPublication("");

                printw("\nBOOK SUCCESSFULLY DELETED!\n\nPress any key to continue . . .");

                getch();

            }



            bookFound = true;

            break;

        }

    }



    if (!bookFound) {

        printw("\nBOOK NOT FOUND!\n\nPress any key to continue . . .");

        getch();

    }



    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');

    std::cin.get();

}



void editBook(int& counter) {

    std::string editIsbn, choice;

    std::string isbn, title, author, edition, publication;

    bool editBookFound = false;



    printw("\nEDIT BOOK\n\n");



    if (counter == 0) {

        printw("THERE IS NO BOOK TO EDIT!\n\nPress any key to continue . . .");

        getch();

        return;

    }



    printw("Enter ISBN: ");

    //refresh();

    std::cin.ignore();

    std::getline(std::cin, editIsbn);



    for (int i = 0; i < counter; i++) {

        if (books[i].getIsbn() == editIsbn) {

            printw("\nBOOK FOUND!\n\n");

            printw("\nDo you want to edit?\n[1] Yes\n[2] No\n\nEnter choice: ");

            refresh();

            std::getline(std::cin, choice);



            if (choice == "1") {

                printw("Enter ISBN: ");

                refresh();

                std::getline(std::cin, isbn);

                printw("Enter Title: ");

                refresh();

                std::getline(std::cin, title);

                printw("Enter Author: ");

                refresh();

                std::getline(std::cin, author);

                printw("Enter Edition: ");

                refresh();

                std::getline(std::cin, edition);

                printw("Enter Publication: ");

                refresh();

                std::getline(std::cin, publication);

                books[i].setIsbn(isbn);

                books[i].setTitle(title);

                books[i].setAuthor(author);

                books[i].setEdition(edition);

                books[i].setPublication(publication);

                printw("\nBOOK EDITED SUCCESSFULLY!\n\nPress any key to continue . . .");

                getch();

            }



            editBookFound = true;

            break;

        }

    }



    if (!editBookFound) {

        printw("\nBOOK NOT FOUND!\n\nPress any key to continue . . .");

        getch();

    }

}



void searchBook(int counter) {

    std::string isbn;

    bool print = false;



    printw("SEARCH BOOK\n\n");

    if (counter == 0) {

        printw("THERE IS NO BOOK TO SEARCH!\n\nPress any key to continue . . .");

        getch();

        return;

    }



    printw("Enter ISBN: ");

    refresh();

    std::getline(std::cin, isbn);



    for (int i = 0; i < counter; i++) {

        if (books[i].getIsbn() == isbn) {

            printw("\nBOOK FOUND!\n\n");

            printw("ISBN: %s\n", books[i].getIsbn().c_str());

            printw("TITLE: %s\n", books[i].getTitle().c_str());

            printw("AUTHOR: %s\n", books[i].getAuthor().c_str());

            printw("EDITION: %s\n", books[i].getEdition().c_str());

            printw("PUBLICATION: %s\n", books[i].getPublication().c_str());

            printw("\n\nPress any key to continue . . .");

            print = true;

        }

    }

    if (!print) {

        printw("\nBOOK NOT FOUND!\n\nPress any key to continue . . .");

    }

    getch();

}



void viewAllBooks(int counter) {

    if (counter == 0) {

        printw("THERE IS NO BOOK TO SHOW!\n\nPress any key to continue . . .");

        getch();

        return;

    }



    printw("VIEW ALL BOOKS\n\n");

    for (int i = 0; i < counter; i++) {

        printw("BOOK DETAILS\n\n");

        printw("ISBN: %s\n", books[i].getIsbn().c_str());

        printw("TITLE: %s\n", books[i].getTitle().c_str());

        printw("AUTHOR: %s\n", books[i].getAuthor().c_str());

        printw("EDITION: %s\n", books[i].getEdition().c_str());

        printw("PUBLICATION: %s\n", books[i].getPublication().c_str());

    }

    printw("Press any key to continue . . .");

    getch();

}



void quit() {

    flag = false;

}

book.cpp:

#include<string>

#include "book.h"



using namespace std;



bookLib::Book::Book(){

	this->isbn = "";

	this->title = "";

	this->author = "";

	this->edition = "";

	this->publication = "";

}



bookLib::Book::Book(string isbn, string title, string author, string edition, string publication){

	this->isbn = isbn;

	this->title = title;

	this->author = author;

	this->edition = edition;

	this->publication = publication;

}



//setters

void bookLib::Book::setIsbn(string a){

this->isbn = a;

}

void bookLib::Book::setTitle(string b){

this->title = b;

}

void bookLib::Book::setAuthor(string c){

this->author = c;

}

void bookLib::Book::setEdition(string d){

this->edition = d;

}

void bookLib::Book::setPublication(string e){

this->publication = e;

}

//setters

string bookLib::Book::getIsbn(){

return this->isbn;

}

string bookLib::Book::getTitle(){

return title;

}

string bookLib::Book::getAuthor(){

return this->author;

}

string bookLib::Book::getEdition(){

return this->edition;

}

string bookLib::Book::getPublication(){

return this->publication;

}

e book.h:

#ifndef BOOK_H

#define BOOK_H



#include <string>



namespace bookLib {

class Book {

	private:

		std::string isbn;

		std::string title;

		std::string author;

		std::string edition;

		std::string publication;

	public:

		//contructor

		Book();

		Book(std::string, std::string, std::string, std::string, std::string);

		//setters - assigning user value to private variables

		void setIsbn(std::string);

		void setTitle(std::string);

		void setAuthor(std::string);

		void setEdition(std::string);

		void setPublication(std::string);

		//getters - getting the values from private variables

		std::string getIsbn();

		std::string getTitle();

		std::string getAuthor();

		std::string getEdition();

		std::string getPublication();

};

}



#endif

Caso vejam algumas melhorias eu ficarei bastante feliz coma ajuda!

Desde já agradeço a todos!

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2. Re: Problemas com lógica - volta ao menu inicial de função int main()

SamL
(usa XUbuntu)

Enviado em 18/02/2024 - 01:41h

Use uma função simples para limpar o buffer de entrada:

void clear_stdin() {

  int c;

  while ((c = getchar()) != '\n' && c != EOF) { }

}

https://stackoverflow.com/questions/7898215/how-can-i-clear-an-input-buffer-in-c

clear_stdin() vc deve usar toda vez que ler da entrada (do stdin), ou seja, quando usar getch(), então usa depois o clear_stdin, se usar scanw, faz depois uma chamada para clear_stdin, etc.

https://nerdki.blogspot.com/ acessa ai, blog dedicado Paranóia!

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