我的while循环没有退出。在调试期间，它非常明确地说stateID等于3.但是，当我添加std::cout << stateID;时，无论调试器告诉我什么，值1总是写入控制台
在代码中，我在输入循环后渲染屏幕。这表明毫无疑问，输入循环正如预期的那样正确退出。此外，如果这还不够，则必须退出以使stateID首先更改。请不要再讨论嵌套循环了。我还在循环之后使用了断点，这些断点被正确击中。
int main()
{
stateID = 1;
GameState* state = new GameStateTitle();
sf::RenderWindow window(sf::VideoMode(1000, 600), "RPG");
//GAME LOOP//
while (stateID != 3)
{//INPUT//
sf::Event event;
while (window.pollEvent(event))
{
switch (event.type)
{
//Window closed
case sf::Event::Closed:
set_next_state(3);
break;
}
}
change_state(state);
//RENDERING//
window.clear(sf::Color::Black);
state->render(window);
window.display();
}
/////////////
window.close();
return 0;
}
void set_next_state(int new_state)
{
//Set the next state to take place
next_state = new_state;
}
void change_state(GameState *current_state)
{
//Check if the next state is null or exit
if (next_state != 0)
{
if (next_state != 3)
delete current_state;
//Set the new state
switch(next_state)
...
}
stateID = next_state;
next_state = 0;
}
}
#include "GameState.hpp"
int main()
{
stateID = STATE_TITLE;
GameState* state = new GameStateTitle();
sf::RenderWindow window(sf::VideoMode(1000, 600), "RPG");
//GAME LOOP//
while (stateID != STATE_EXIT)
{
//INPUT//
sf::Event event;
while (window.pollEvent(event))
{
switch (event.type)
{
//Window closed
case sf::Event::Closed:
set_next_state(STATE_EXIT);
break;
}
}
///////////
////LOGIC//
state->logic();
///////////
change_state(state);
//RENDERING//
window.clear(sf::Color::Black);
state->render(window);
std::cout << stateID;
window.display();
/////////////
}
///////////////
window.close();
return 0;
}
#pragma once
#include <SFML/Graphics.hpp>
//DEFINITIONS ETC//
enum GAME_STATES {
STATE_NULL,
STATE_TITLE,
STATE_BATTLE,
STATE_EXIT
};
///////////////////
//Game State Class//
class GameState
{
public:
virtual void input(void) = 0;
virtual void logic(void) = 0;
virtual void render(sf::RenderWindow &window) = 0;
};
////////////////////
//FUNCTIONS//
void set_next_state(int new_state);
void change_state(GameState *current_state);
/////////////
//VARIABLES//
static int stateID;
static int next_state;
/////////////
//Title GameState Class//
class GameStateTitle : public GameState
{
private:
sf::Texture img_title;
sf::Sprite bgr_title;
public:
GameStateTitle(void);
~GameStateTitle(void);
void input(void);
void logic(void);
void render(sf::RenderWindow &window);
};
/////////////////////////
//Battle GameState Class//
class GameStateBattle : public GameState
{
private:
sf::Image img_left;
sf::Image img_right;
public:
GameStateBattle(void);
~GameStateBattle(void);
void input(void);
void logic(void);
void render(sf::RenderWindow &window);
};
//////////////////////////
#include "GameState.hpp"
//Game state general functions
void set_next_state(int new_state)
{
//Set the next state to take place
next_state = new_state;
}
void change_state(GameState *current_state)
{
//Check if the next state is null or exit
if (next_state != STATE_NULL)
{
if (next_state != STATE_EXIT)
delete current_state;
//Set the new state
switch(next_state)
{
case STATE_TITLE:
current_state = new GameStateTitle;
break;
case STATE_BATTLE:
current_state = new GameStateBattle;
break;
}
stateID = next_state;
next_state = STATE_NULL;
}
}
//The functions of the title state
GameStateTitle::GameStateTitle(void)
{
//Load texture
img_title.loadFromFile("title_screen.png");
//Set texture to background
bgr_title.setTexture(img_title);
}
GameStateTitle::~GameStateTitle(void)
{
}
void GameStateTitle::input(void)
{
}
void GameStateTitle::logic(void)
{
}
void GameStateTitle::render(sf::RenderWindow &window)
{
window.draw(bgr_title);
}
//The functions of the battle state
GameStateBattle::GameStateBattle(void)
{
}
GameStateBattle::~GameStateBattle(void)
{
}
void GameStateBattle::input(void)
{
}
void GameStateBattle::logic(void)
{
}
void GameStateBattle::render(sf::RenderWindow &window)
{
}
答案 0 :(得分：5)
您有两个while循环。在内循环退出之前，永远不会测试外部while中的条件。
考虑只使用一个循环，只有一个条件。
sf::Event event;
while ( (stateID != 3) && window.pollEvent(event)) {
}
答案 1 :(得分：1)
您正在突破switch，而不是while。
以下程序（尝试）复制您的代码。 它按预期工作，两个循环在它们应该结束时结束。
不过，这就是我们所说的short, contained, correct example。 正如可编辑一样，使用stateID之类的全局变量或3中的while (stateID != 3)之类的幻数是不好的形式，而不是专业人士的标记。
您的计划如何偏离下面的计划？
#define STATE_TITLE 2
#define STATE_BATTLE 3
#define STATE_NULL 0
int stateID;
int next_state;
struct Event
{
Event(int Num) : type(Num){}
Event() : type( 5 ){} // random number grater than 1
enum Type
{
Closed = 1 // equivalent to sf::Event::Closed
};
int type;
};
class Window
{
public:
int pollEvent( Event& Ev )
{
return --Ev.type;
}
};
void set_next_state(int new_state)
{
next_state = new_state;
}
void change_state()
{
if (next_state != STATE_NULL)
{
stateID = next_state;
next_state = STATE_NULL;
}
}
int _tmain()
{
stateID = STATE_TITLE;
Window window;
//GAME LOOP//
while (stateID != 3)
{//INPUT//
Event event;
// note that there is at least one event with a Closed type before window.pollEvent(event) return false (0)
while (window.pollEvent(event))
{
switch (event.type)
{
//Window closed
case Event::Closed:
set_next_state(3);
break;
}
}
change_state();
}
return 0;
}
答案 2 :(得分：0)
我将函数change_state更改为以下内容：
void change_state(GameState *current_state, int &ID)
{
//Check if the next state is null or exit
if (next_state != STATE_NULL)
{
if (next_state != STATE_EXIT)
delete current_state;
//Set the new state
switch(next_state)
{
case STATE_TITLE:
current_state = new GameStateTitle;
break;
case STATE_BATTLE:
current_state = new GameStateBattle;
break;
}
ID = next_state;
next_state = STATE_NULL;
}
}
问题必须在stateID的声明范围内，因为在此功能中从未改变过。