QT之贪吃蛇

Posted 2020-09-06

1、开始界面

 

对话框设置：设置对话框控件以及标题

 

1. GameStart::GameStart(QDialog *parent)
2.     : QDialog(parent)
3. {
4.  
5.     createWidgets();
6.     setWindowTitle(tr("Snake"));
7. }

 

设置3个按钮，连接三种操作：开始游戏，获得历史排名，结束游戏。

 

1.     beginGame=new QPushButton(tr("start"));
2.     beginGame->setFixedSize(120, 30);
3.     beginGame->setFont(font);
4.     connect(beginGame, SIGNAL(clicked()), this, SLOT(startGame()));
5.  
6.     endGame=new QPushButton(tr("end"));
7.     endGame->setFixedSize(120, 30);
8.     endGame->setFont(font);
9.     connect(endGame, SIGNAL(clicked()), this, SLOT(close()));
10.  
11.     GameRank=new QPushButton(tr("rank"));
12.     GameRank->setFixedSize(120, 30);
13.     GameRank->setFont(font);
14.     connect(GameRank, SIGNAL(clicked()), this, SLOT(loadRank()));

 

设置游戏等级选项，含有3个等级。

 

1.     GameLevelCombo=new QComboBox(this);
2.     GameLevelCombo->setFixedSize(120, 30);
3.     GameLevelCombo->setFont(font);
4.     GameLevelCombo->addItem(tr("elementary"));
5.     GameLevelCombo->addItem(tr("intermediate"));
6.     GameLevelCombo->addItem(tr("advanced"));
7.     connect(GameLevelCombo, SIGNAL(activated(const QString &)), this, SLOT(getGameLevel()));

 

设置label和lineedit，用于输入玩家姓名。

 

1.     NameLabel=new QLabel(tr("player"));
2.     NameLabel->setFixedSize(120, 30);
3.     NameLabel->setFont(font);
4.     NameEdit=new QLineEdit;
5.     NameEdit->setFixedSize(200, 30);
6.     connect(NameEdit, SIGNAL(textChanged(const QString &)), this, SLOT(setName()));

 

利用QTextEdit来显示排名信息。

 

1.     RankText=new QTextEdit(this);
2.     RankText->setStyleSheet("background:argb(248, 248, 255, 0%)");
3.     RankLabel=new QLabel(tr("show rank"));
4.     RankLabel->setFixedSize(100, 30);
5.     RankLabel->setFont(font);

 

布局：

 

1.     QVBoxLayout *LeftLayout=new QVBoxLayout;
2.     LeftLayout->addWidget(beginGame);
3.     LeftLayout->addWidget(GameRank);
4.     LeftLayout->addWidget(GameLevelCombo);
5.     LeftLayout->addWidget(endGame);
6.  
7.     QVBoxLayout *RightLayout=new QVBoxLayout;
8.     RightLayout->addWidget(RankLabel);
9.     RightLayout->addWidget(RankText);
10.  
11.     QHBoxLayout *TopLayout=new QHBoxLayout;
12.     TopLayout->addWidget(NameLabel);
13.     TopLayout->addWidget(NameEdit);
14.  
15.  
16.     QHBoxLayout *BelowLayout=new QHBoxLayout;
17.     BelowLayout->addLayout(LeftLayout);
18.     BelowLayout->addLayout(RightLayout);
19.  
20.     QVBoxLayout *MainLayout=new QVBoxLayout;
21.     MainLayout->addLayout(TopLayout);
22.     MainLayout->addLayout(BelowLayout);
23.     setLayout(MainLayout);

 

玩家名字获得、获得排名信息、产生游戏等级的函数实现：

 

1. void GameStart::setName(){
2.     player=NameEdit->text();
3.  
4. }
5.  
6.  
7. void GameStart::getGameLevel(){
8.     QString LevelString=GameLevelCombo->currentText();
9.     if(LevelString==tr("elementary"))
10.         GameLevel=1;
11.     else if(LevelString==tr("intermediate"))
12.         GameLevel=2;
13.     else if(LevelString==tr("advanced"))
14.         GameLevel=3;
15.     else
16.         GameLevel=1;
17. }
18.  
19.  
20.  
21.  
22. void GameStart::loadRank(){
23.     QFile file("H:/soft programme/QTMySnaker/snake/Rank.txt");
24.     if(!file.open(QFile::ReadOnly)){
25.         QMessageBox::warning(this, tr("load rank"), tr("cannot load rank file %1").arg(file.fileName()));
26.         return;
27.     }
28.      QTextStream in(&file);
29.      RankText->setPlainText(in.readAll());
30.  
31. }

 

对于游戏界面调出，则要求能够隐藏当前对话框，并且终止当前线程，而可以去执行游戏界面的线程，那么需要在游戏界面重新实现一个执行函数exec()。

 

1. void GameStart::startGame(){
2.  
3.     this->close();
4.  
5.     ImageShow ImageShow_M1(player,GameLevel);
6.     ImageShow_M1.exec();
7.  
8.     this->show();
9.     this->exec();
10.  
11.  
12. }

 

如果仅仅是游戏界面用show()函数，则游戏界面不会产生控件，仅仅会出现一个主窗口。这就是模式和非模式显示，模式不仅显示界面而且会锁定在这个界面上，从而执行操作。一般QDialog有自己的exec()函数，而QWidget没有，这就需要在QWidget中实现一个。

 

2、游戏界面

 

初始化、定义计时器：

1. ImageShow::ImageShow(const QString player, const int game_level):
2.     player(player), game_level(game_level){
3.  
4.  
5.     setWindowTitle(tr("In Game..."));
6.     setFixedSize(ROWS+20, COLUMNS+50);
7.     InitSnake();
8.  
9.     Timer=new QTimer(this);
10.     connect(Timer, SIGNAL(timeout()),this, SLOT(timeout()));
11.     Timer->start(1000/game_level);
12.  
13. }

 

1. void ImageShow::InitSnake(){
2.  
3.     game_score = 0;
4.     IsOver=false;
5.     direction=3;//right
6.  
7.     body_x = new vector<char>;
8.     body_y = new vector<char>;
9.  
10.     for (int i = 4; i >= 1; i--) {
11.         body_x->push_back(1);
12.         body_y->push_back(i);//初始化具有1个蛇头和3个蛇身的蛇
13.  
14.     }
15.     food_x = 3;
16.     food_y = 5;
17.  
18.  
19. }

 

1. void ImageShow::timeout(){
2.  
3.      IsOver=walk();
4.      if(IsOver == true){
5.          Timer->stop();
6.  
7.  
8.          int r=QMessageBox::warning(this,tr("save rank"), tr("geme is over!\\n"
9.                                                              "Do you want to save the game results?"),
10.                                      QMessageBox::Yes|QMessageBox::No);
11.           if(r==QMessageBox::Yes)
12.             saveRank();
13.          return;
14.      }
15.  
16.      update();
17.  
18.  
19. }

根据游戏等级，产生了不同时间限定，时间到就会去执行蛇行走，然后再绘制图像，通过调用了update函数实现绘制事件。

 

1. bool ImageShow::walk() {
2.  
3.  
4.  
5.     switch (direction) {
6.     case 1: {
7.         body_x->insert(body_x->begin(), (*body_x)[0]);
8.         body_x->pop_back();
9.         body_y->insert(body_y->begin(), (*body_y)[0] - 1);
10.         body_y->pop_back();
11.         break;
12.     }//左移动
13.     case 2: {
14.         body_x->insert(body_x->begin(), (*body_x)[0] - 1);
15.         body_x->pop_back();
16.         body_y->insert(body_y->begin(), (*body_y)[0]);
17.         body_y->pop_back();
18.         break;
19.     }//向上移动
20.     case 3: {
21.         body_x->insert(body_x->begin(), (*body_x)[0]);
22.         body_x->pop_back();
23.         body_y->insert(body_y->begin(), (*body_y)[0] + 1);
24.         body_y->pop_back();
25.         break;
26.     }//向右移动
27.     case 4: {
28.         body_x->insert(body_x->begin(), (*body_x)[0] + 1);
29.         body_x->pop_back();
30.         body_y->insert(body_y->begin(), (*body_y)[0]);
31.         body_y->pop_back();
32.         break;
33.     }//向下移动
34.  
35.     default: ;
36.  
37.  
38.     }
39.  
40.  
41.     if (((*body_x)[0] == food_x) && ((*body_y)[0] == food_y)) {
42.         body_x->push_back(body_x->back());
43.         body_y->push_back(body_y->back());
44.         game_score++;
45.         produce();
46.     }//吃下食物
47.  
48.     if (((*body_x)[0] == 0) || ((*body_x)[0] == (ROWS/8)) || ((*body_y)[0] == 0) || ((*body_y)[0] == (COLUMNS/8))) {
49.  
50.  
51.         return true;//蛇撞墙，游戏失败
52.  
53.     }
54.     return false;
55.  
56.  
57.  
58.  
59. }

 

1. void ImageShow::paintEvent(QPaintEvent *){
2.  
3.     QPainter *painter = new QPainter(this);
4.     painter->setRenderHint(QPainter::Antialiasing, true);
5.  
6.     QPen ThinPen(palette().foreground(), 1);
7.  
8.     QColor LightSlateBlue(132, 112, 255);
9.     QPen ThickPen(LightSlateBlue, 4);
10.  
11.     painter->save();
12.     painter->translate(10, 40);
13.     painter->setPen(ThickPen);
14.     painter->setBrush(LightSlateBlue);
15.     painter->drawLine(0, 0, ROWS, 0);
16.     painter->drawLine(0, 0, 0, COLUMNS);
17.     painter->drawLine(ROWS, 0, ROWS, COLUMNS);
18.     painter->drawLine(0, COLUMNS, ROWS, COLUMNS);
19.  
20.     painter->restore();
21.  
22.  
23.     QColor brown(255,64,64);
24.     QPen textPen(brown, 4);
25.     painter->setPen(textPen);
26.     QFont font=painter->font();
27.     font.setPixelSize(20);
28.     painter->setFont(font);
29.     const QRect rectangle1=QRect(50, 2, 150, 25);
30.     QRect boundingrect;
31.     painter->drawText(rectangle1, 0, player, &boundingrect);
32.     const QRect rectangle2=QRect(130, 2, 150, 25);
33.     painter->drawText(rectangle2, 0, tr("Game Level: %1").arg(game_level), &boundingrect);
34.     const QRect rectangle3=QRect(300, 2, 150, 25);
35.     painter->drawText(rectangle3, 0, tr("game score: %1").arg(game_score), &boundingrect);
36.  
37.     painter->save();
38.     painter->rotate(270);
39.     painter->translate(-40, 10);
40.  
41.     QPoint FoodPoint(-food_x*8,food_y*8);
42.  
43.     QRadialGradient RadialGradient(-food_x*8, food_y*8, 6, -food_x*8, food_y*8);
44.     RadialGradient.setColorAt(0, Qt::green);
45.     RadialGradient.setColorAt(1.0, Qt::darkGreen);
46.     painter->setPen(Qt::NoPen);
47.     painter->setBrush(RadialGradient);
48.     painter->drawEllipse(FoodPoint, 6, 6);
49.  
50.     QPoint SnakeHeadPoint(-8*((*body_x)[0]), 8*((*body_y)[0]));
51.     QConicalGradient ConicalGradient(-8*((*body_x)[0]), 8*((*body_y)[0]), 270);
52.     ConicalGradient.setColorAt(0,Qt::red);
53.     ConicalGradient.setColorAt(1,Qt::darkRed);
54.     painter->setPen(ThinPen);
55.     painter->setBrush(ConicalGradient);
56.     painter->drawEllipse(SnakeHeadPoint, 5, 5);
57.  
58.     QColor LightSalmon(255,160,122);
59.     painter->setPen(ThinPen);
60.     painter->setBrush(LightSalmon);
61.  
62.     for(int i=1;i<body_x->size();i++){
63.         painter->drawRect(-8*((*body_x)[i])-4, 8*((*body_y)[i])-4,8,8);
64.  
65.     }
66.  
67.     painter->restore();
68.  
69.  
70.  
71.  
72. }

 

对于蛇的移动和控制，通过重载keyPressEvent函数来实现。

 

1. void ImageShow::keyPressEvent(QKeyEvent *KeyEvent){
2.  
3.     switch(KeyEvent->key()){
4.     case Qt::Key_Left: {direction = 1;break;}
5.     case Qt::Key_Up:{direction=2;break;}
6.     case Qt::Key_Right:{direction=3;break;}
7.     case Qt::Key_Down:{direction=4;break;}
8.     default:break;
9.     }
10.  
11.  
12.      QWidget::keyPressEvent(KeyEvent);
13.  
14. }

 

保存游戏结果，并且将原来游戏历史记录根据得分高低排序。

 

1. void ImageShow::saveRank(){
2.  
3.     archive archive_now;
4.     archive archive_history[10];
5.     int archive_num=0;
6.  
7.     string PlayerString=player.toStdString();
8.     strcpy(archive_now.player_temp, PlayerString.c_str());
9.     archive_now.game_leve_temp=game_level;
10.     archive_now.game_score_temp=game_score;
11.  
12.     QFile File("H:/soft programme/QTMySnaker/snake/Rank.txt");
13.     if(!File.open(QIODevice::ReadWrite))
14.         return;
15.     QTextStream InOut(&File);
16.     while(!File.atEnd()){
17.         QString player_string;
18.         InOut>>player_string>>archive_history[archive_num].game_leve_temp
19.                 >>archive_history[archive_num].game_score_temp;
20.         string PlayerString=player_string.toStdString();
21.         strcpy(archive_history[archive_num].player_temp, PlayerString.c_str());
22.         archive_num++;
23.     }
24.  
25.  
26.  
27.  
28.     for(int i=0;i<=archive_num;i++){
29.  
30.         if(archive_now.game_score_temp>archive_history[i].game_score_temp){
31.           for(int j=archive_num;j>=i+1;j--){
32.  
33.               archive_history[j]=archive_history[j-1];
34.           }
35.             archive_history[i]=archive_now;
36.             break;
37.         }
38.         else if(i==archive_num){
39.             archive_history[archive_num]=archive_now;
40.         }
41.  
42.     }
43.  
44.     for(int i=0;i<=archive_num;i++){
45.         InOut<<archive_history[i].player_temp<<‘\\t‘
46.             <<archive_history[i].game_leve_temp<<‘\\t‘
47.            <<archive_history[i].game_score_temp<<‘\\n‘;
48.     }
49.     File.close();
50.  
51.  
52. }

 

接下来就是如何让这个界面能够在开始界面点击开始后可以执行，通过利用一个QEventLoop，可以将执行锁定住，然后为了退出循环，则可以通过关闭事件来调用其退出。

 

1. void ImageShow::exec(){
2.  
3.     this->show();
4.     QEventLoop loop;
5.     m_loop=&loop;
6.     loop.exec();
7.  
8.  
9. }
10.  
11. void ImageShow::closeEvent(QCloseEvent *event){
12.     this->hide();
13.     m_loop->exit();
14.     event->accept();
15.  
16. }