SFML中的纹理超出范围

Question

Well, I'm trying to make a menu using SFML 2.1. I have a 'something.h' header file and two source files. For the buttons, I've created a texture file. Now, since I want all the menu buttons to have the same texture, I was trying to declare the texture globally. I tried a couple of ways to do this. I tried to declare it just before all the class declarations in something.h, but I found out that you can't use texture.loadFromFile("blahblah") without a function. SO, I decided to make a class for this, and the following is the code.

Something.h

#include<SFML/Graphics.hpp>
#include<iostream>
class Textureinitialize
{
public:
    sf::Texture texture;
    sf::Font font;
    void loadtexture(const std::string& texturestring);       //Specify file-name of texture
    void loadfont(const std::string& fontstring);             //Specify file-name of font
};
class Menubutton
{
public:
    sf::Sprite menubuttonsprite;
    sf::Text menubuttontext;
    sf::Vector2i spritekaposition;
    void loadthesprite(Textureinitialize obj1);               //Load sprite from Texture and Text from font
    void loadtexturepos(sf::IntRect rect1);                   //Load the sprite rectangle from the Texture
    void spriteposition(sf::Vector2i originpos);              //Specify position of button on the screen
    void texttodisplay(std::string displaystring);            //String to be displayed in button
    void positionoftext(sf::Vector2i textpos,int textsize);   //Set position and size of text to be displayed
};

This gave no error, but the menu button sprite does not display on the screen. I think the problem is with the loading of the texture. I looked around, and found that somehow the texture is going out of scope. Please could anyone help me?

EDIT:
I guess more code is the need of the hour. Here are the contents of the two source files I mentioned.

Something.cpp

#include "Menudata.h"
void Textureinitialize::loadtexture(const std::string& texturestring)
{
    if(!texture.loadFromFile(texturestring))
        std::cout<<"\nFailed to load textures";
}
void Textureinitialize::loadfont(const std::string& fontstring)
{
    if(!font.loadFromFile(fontstring))
        std::cout<<"\nFailed to load font";
}
void Menubutton::loadthesprite(Textureinitialize obj1)
{
        menubuttonsprite.setTexture(obj1.texture);
        menubuttontext.setFont(obj1.font);
}
void Menubutton::spriteposition(sf::Vector2i originpos)
{
    spritekaposition.x=originpos.x;
    spritekaposition.y=originpos.y;
    menubuttonsprite.setPosition(originpos.x,originpos.y);
}
void Menubutton::loadtexturepos(sf::IntRect rect1)
{
    menubuttonsprite.setTextureRect(rect1);
}
void Menubutton::texttodisplay(std::string displaystring)
{
    menubuttontext.setString(displaystring);
}
void Menubutton::positionoftext(sf::Vector2i textpos,int textsize)
{
    menubuttontext.setPosition(spritekaposition.x+textpos.x,spritekaposition.y+textpos.y);
    menubuttontext.setCharacterSize(textsize);
    menubuttontext.setColor(sf::Color::Red);
}

Main.cpp

#include "Menudata.h"
int main()
{
    Textureinitialize a;
    a.loadtexture("Menubutton.tga");
    a.loadfont("arial.ttf");
    Menubutton b;
    b.loadthesprite(a);
    b.loadtexturepos(sf::IntRect(0,0,80,48));
    b.spriteposition(sf::Vector2i(50,50));
    b.texttodisplay("Hello!");
    b.positionoftext(sf::Vector2i(50,14),20);
    sf::RenderWindow window(sf::VideoMode(200,200),"My Window");
    while(window.isOpen())
    {
        sf::Event event;
        while(window.pollEvent(event))
        {
            if(event.type==sf::Event::Closed)
                window.close();
            if(event.type==sf::Event::MouseButtonPressed)
            {
                b.loadtexturepos(sf::IntRect(0,48,80,48));
                if(event.mouseButton.button==sf::Mouse::Left)
                    std::cout<<"\nHello!!!";
            }
            if(event.type==sf::Event::MouseButtonReleased)
                b.loadtexturepos(sf::IntRect(0,0,80,48));
        }
        window.clear(sf::Color::Green);
        window.draw(b.menubuttonsprite);
        window.draw(b.menubuttontext);
        window.display();
    }
return 0;
}

The reason I thought the texture is going out of scope was that I read somewhere on Google that if you're getting a white rectangle instead of the image, you might have the said issue. Also, I just noticed that I couldn't see any text in the white box. I do have a function which displays text on the buttons in the class 'Menubutton'. I think the problem might be in the initialization of font. I hope what I've done in the class 'Textureinitialize' isn't wrong. I guess the problem might lie there.

Answer 1

As far as managing SFML resources goes, eg textures, I can only recommend this template:

https://github.com/LaurentGomila/SFML-Game-Development-Book/tree/master/02_Resources/Include/Book

This is a, in my opionion, simple way to access the texture whenever you need it to construct your buttons

PS: To improve readability of your code, I suggest using notations such as my_function or myFunction, instead of myfunction (all lowercase).