QT贪吃蛇程序求解！//带注释解决方法

#include <QMessageBox>#include <QTime>enum  Direction{d_up,d_down,d_left,d_right};//o代表d_up? 1代表d_down? 10代表d_left?class  Snake:public  QDialog{        Q_OBJECT        private:        QLabel  *food;        QList<QLabel*>  data;        int   maxlen;        int   speed;        Direction  dire; //枚举类型的变量？        public :        Snake();        ~Snake();        public slots:        void  snakemove();        public:        void  keyPressEvent(QKeyEvent *e);        void timerEvent(QTimerEvent *e);        /*生成食物的函数 */        QLabel*  getFood(); };#endif // SNAKE_H

#include "Snake.h"#include <QKeyEvent>#include <QTime>Snake::Snake(){ qsrand(QTime::currentTime().msec()); this->resize(600,500); data.push_back(getFood());// data[0]->show();dire=d_right;speed=20;this->startTimer(300);getFood();}Snake::~Snake(){}void  Snake::snakemove(){      int  nhx=data[0]->x();      int  nhy=data[0]->y();      if(nhx==food->x()&&nhy==food->y()){            data.push_back(food);            food=getFood();            food->show();      }      switch(dire){              case  d_up:               nhy=nhy-20;               break;              case d_down:               nhy=nhy+20;               break;              case d_left:               nhx=nhx-20;               break;              case d_right:              nhx=nhx+20;              break;      }      /*从data中的最后一个元素  */      for(int i=data.size()-1;i>0;i--){            data[i]->move(data[i-1]->x(),data[i-1]->y());      }      data[0]->move(nhx,nhy);      if(nhx<=0||nhx>=this->width()||         nhy<=0||nhy>=this->height()){          this->close();      }}void  Snake::keyPressEvent(QKeyEvent *e){       /*判断 到底那个键被按下*/      if(e->key()==Qt::Key_Up){        dire=d_up;      }else if(e->key()==Qt::Key_Down){        dire=d_down;     }else if(e->key()==Qt::Key_Left){        dire=d_left;     }else if(e->key()==Qt::Key_Right){          dire=d_right;      }else{         ;      }}void  Snake::timerEvent(QTimerEvent *e){       snakemove();}/*生成食物的函数 */QLabel*  Snake::getFood(){//为啥返回值类型是QLabel类型的指针？          food=new QLabel(this);          food->resize(20,20);          food->setAutoFillBackground(true);          food->setFrameShape(QFrame::Box);          food->setPalette(QPalette(QColor(255,0,0)));          int  x=this->width();          int  y=this->height();          food->move((qrand()%(x/20))*20,                     (qrand()%(y/20))*20);          

#include "Snake.h"#include <QApplication>int main(int argc,char**argv){QApplication  app(argc,argv);     Snake  sn;     sn.show();//show();函数的作用是通过sn调用头文件的Snake这个类内所有函数？return app.exec();}