错误：没有匹配的函数调用 &#39;sf::RenderWindow::draw(<unresolved overloaded function type> )&#39; SFML C++

Question

I tried to create a Button class and use it with SFML, unfortunately, I get the error:

E:\...\something.cpp:154:40: error: no matching function for call to 'sf::RenderWindow::draw(<unresolved overloaded function type>)'
                 sfmlWin.draw(buttt.Butt);
                                        ^

This is the code:

#include <iostream>
#include <functional>
#include <SFML/Graphics.hpp>
using namespace std;
using namespace sf;

void onclic(){cout << "Clicked";}

class Button{
public:
    string ButtonText;
    Color color;
    int sizee;
    int x;
    int y;
    RenderWindow winname;
    void func(){cout << "Something";}

    void Butt(string ButtonText, Color color, int sizee, int x, int y, function<void()> funcc, RenderWindow& winname){

        Text tt;
        tt.setString(ButtonText);
        tt.setColor(color);
        tt.setPosition(x, y);
        tt.setCharacterSize(sizee);
        Event e;
        while (winname.pollEvent(e)) {

            switch (e.type) {
        case Event::MouseButtonPressed:
            funcc();
            }
        }
    }
};

int main() {

    sf::RenderWindow sfmlWin;
    sfmlWin.setTitle("Hello!");
    sf::Font font;
    while (sfmlWin.isOpen()) {
        sf::Event e;
        while (sfmlWin.pollEvent(e)) {
            switch (e.type) {
            case sf::Event::EventType::Closed:

                Text t;
                t.setString("Something");
                sfmlWin.draw(t);
                Button buttt;
                Color col(0,255,0);
                buttt.Butt("CLICK!", col, 20, 50, 50, onclic, sfmlWin);
                sfmlWin.draw(buttt.Butt);
            }
        }
        sfmlWin.clear();
        sfmlWin.display();
    }
    return 0;
}

Where did I go wrong?

If a Button class cannot be achieved in this way, is there any other way to implement it?

Answer 1

Your class Button must be derived from sf::Drawable and in there you override the draw method:

class Button : public sf::Drawable
{
protected:
    void draw (RenderTarget& target, RenderStates states) const override
    {
        // your draw implementation, which is called Butt() I think
    }
}

Then you pass it in your main like this:

Button button;
sfmlWin.draw(button);