我正在用 C++ 制作游戏,但我的派生类有问题。我有一个名为 GameScreen 的基类,它有一个没有语句的虚拟 void draw() 函数。我还有一个名为 MenuScreen 的派生类,它也有一个虚拟 void draw() 函数和一个来自 MenuScreen 的名为 TestMenu 的派生类,它也有一个 void draw() 函数。在我的程序中,我有一个 GameScreen 列表,我有一个 GameScreen 迭代器通过调用每个 GameScreens draw() 函数。
问题是我在 GameScreen 列表中放置了一个 TestMenu 对象。不是迭代器调用 TestMenu 的 draw() 函数,而是调用 GameScreen 类的 draw() 函数。有谁知道我如何调用 TestMenu 的 draw() 函数而不是 GameScreen 中的函数。
这是功能:
// Tell each screen to draw itself.
//gsElement is a GameScreen iterator
//gsScreens is a list of type GameScreen
void Draw()
{
for (gsElement = gsScreens.begin(); gsElement != gsScreens.end(); gsElement++)
{
/*if (gsElement->ssState == Hidden)
continue;*/
gsElement->Draw();
}
}
这是我的课程的副本:
class GameScreen {
public:
string strName;
bool bIsPopup;
bool bOtherScreenHasFocus;
ScreenState ssState;
//ScreenManager smScreenManager;
GameScreen(string strName){
this->strName = strName;
}
//Determine if the screen should be drawn or not
bool IsActive(){
return !bOtherScreenHasFocus &&
(ssState == Active);
}
//------------------------------------
//Load graphics content for the screen
//------------------------------------
virtual void LoadContent(){
}
//------------------------------------
//Unload content for the screen
//------------------------------------
virtual void UnloadContent(){
}
//-------------------------------------------------------------------------
//Update changes whether the screen should be updated or not and sets
//whether the screen should be drawn or not.
//
//Input:
// bOtherScreenHasFocus - is used set whether the screen should update
// bCoveredByOtherScreen - is used to set whether the screen is drawn or not
//-------------------------------------------------------------------------
virtual void Update(bool bOtherScreenHasFocus, bool bCoveredByOtherScreen){
this->bOtherScreenHasFocus = bOtherScreenHasFocus;
//if the screen is covered by another than change the screen state to hidden
//else set the screen state to active
if(bCoveredByOtherScreen){
ssState = Hidden;
}
else{
ssState = Active;
}
}
//-----------------------------------------------------------
//Takes input from the mouse and calls appropriate actions
//-----------------------------------------------------------
virtual void HandleInput(){
}
//----------------------
//Draw content on screen
//----------------------
virtual void Draw(){
}
//--------------------------------------
//Deletes screen from the screen manager
//--------------------------------------
void ExitScreen(){
//smScreenManager.RemoveScreen(*this);
}
};
class MenuScreen: public GameScreen{
public:
vector <BUTTON> vbtnMenuEntries;
MenuScreen(string strName):GameScreen(strName){
}
virtual void Update(bool bOtherScreenHasFocus, bool bCoveredByOtherScreen){
GameScreen::Update(bOtherScreenHasFocus, bCoveredByOtherScreen);
for(unsigned int i = 0; i < vbtnMenuEntries.size(); i++){
vbtnMenuEntries[i].IsPressed();
}
}
virtual void Draw(){
GameScreen::Draw();
for(unsigned int i = 0; i < vbtnMenuEntries.size(); i++)
vbtnMenuEntries[i].Draw();
}
};
class testMenu : public MenuScreen{
public:
vector<OBJECT> test;
//OBJECT background3();
// OBJECT testPic(512, 384, buttonHover.png, 100, 40, 100, 40);
// BUTTON x(256, 384, buttonNormal.png, buttonHover.png, buttonPressed.png, 100, 40, test());
bool draw;
testMenu():MenuScreen("testMenu"){
OBJECT background3(1, 1, 0, TEXT("background.png"), 1, 1, 1024, 768);
OBJECT testPic(512, 384,0, TEXT("buttonHover.png"), 1, 1, 100, 40);
test.push_back(background3);
test.push_back(testPic);
//background3.Init(int xLoc, int yLoc, int zLoc, LPCTSTR filePath, int Rows, int Cols, int Width, int Height)
//test.push_back(background3);
// vbtnMenuEntries.push_back(x);
draw = false;
}
void Update(bool bOtherScreenHasFocus, bool bCoveredByOtherScreen){
MenuScreen::Update(bOtherScreenHasFocus, bCoveredByOtherScreen);
//cout << "X" << endl;
/*if(MouseLButton == true){
testMenu2 t;
smManager.AddScreen(t);
}*/
}
void Draw(){
//background3.Draw();
test[0].Draw();
test[1].Draw();
MenuScreen::Draw();
///*if(draw){*/
// testPic.Draw();
//}
}
/*void test(){
draw = true;
}*/
};