QT QGraphicsView QGraphicsScene用法

graphics view 框架结构主要包含三个类，场景类（qgraphicsscene），视图类(qgraphicsview)和图元类(qgraphicsitem)

 

 

 

 

 

#include "dialog.h"

#include <QPixmap>

#include "ui_dialog.h"

// 游戏的初始速度

static const qreal INITSPEED = 500;

Dialog::Dialog(QWidget *parent) :

QDialog(parent),

ui(new Ui::Dialog)

{

ui->setupUi(this);

//设置场景

QGraphicsScene *scene = new QGraphicsScene();

scene->setSceneRect(0,0, 750, 580);

ui->graphicsView->setScene(scene);

//scene->setBackgroundBrush(QPixmap(":/images/background.png"));

topLine = scene->addLine(100,20, 400, 20);

bottomLine = scene->addLine(100,520, 400, 520);

leftLine = scene->addLine(100, 20, 100, 520);

rightLine = scene->addLine(400,20,400,520);

// 当前方块组和提示方块组

boxGroup = new BoxGroup;

connect(boxGroup, SIGNAL(needNewBox()), this, SLOT(clearFullRows()));

connect(boxGroup, SIGNAL(gameFinished()), this, SLOT(gameOver()));

scene->addItem(boxGroup);

nextBoxGroup = new BoxGroup;

scene->addItem(nextBoxGroup);

startGame();

}

// 开始游戏

void Dialog::startGame()

{

initGame();

}

// 初始化游戏

void Dialog::initGame()

{

boxGroup->createBox(QPointF(300, 70));

boxGroup->setFocus();

boxGroup->startTimer(INITSPEED);

gameSpeed = INITSPEED;

nextBoxGroup->createBox(QPointF(640, 70));

}

// 清空满行

void Dialog::clearFullRows()

{

// 获取比一行方格较大的矩形中包含的所有小方块

for (int y = 429; y > 50; y -= 20) {

QList<QGraphicsItem *> list = ui->graphicsView->scene()->items(199, y, 202, 22, Qt::ContainsItemShape, Qt::AscendingOrder);

// 如果该行已满

if (list.count() == 10) {

foreach (QGraphicsItem *item, list) {

mybox *box = (mybox*) item;

box->deleteLater();

}

// 保存满行的位置

rows << y;

}

}

// 如果有满行，下移满行上面的各行再出现新的方块组

// 如果没有满行，则直接出现新的方块组

if(rows.count() > 0) {

moveBox();

} else {

boxGroup->createBox(QPointF(300, 70), nextBoxGroup->getCurrentShape());

// 清空并销毁提示方块组中的所有小方块

nextBoxGroup->clearBoxGroup(true);

nextBoxGroup->createBox(QPointF(500, 70));

}

}

// 下移满行上面的所有小方块

void Dialog::moveBox()

{

// 从位置最靠上的满行开始

for (int i = rows.count(); i > 0;  --i) {

int row = rows.at(i - 1);

foreach (QGraphicsItem *item,ui->graphicsView->scene()->items(199, 49, 202, row - 47, Qt::ContainsItemShape, Qt::AscendingOrder)) {

item->moveBy(0, 20);

}

}

// 更新分数

updateScore(rows.count());

// 将满行列表清空为0

rows.clear();

// 等所有行下移以后再出现新的方块组

boxGroup->createBox(QPointF(300, 70), nextBoxGroup->getCurrentShape());

nextBoxGroup->clearBoxGroup(true);

nextBoxGroup->createBox(QPointF(500, 70));

}

void Dialog::updateScore(const int fullRowNum)

{

// 更新分数

}

void Dialog::gameOver()

{

// 游戏结束

}

Dialog::~Dialog()

{

delete ui;

}