keyevent.h
/*** 书本:【Qt5开发及实例】* 功能:实现键盘控制* 文件:keyevent.h* 时间:2015年2月8日11:48:47* 作者:cutter_point*/#ifndef KEYEVENT_H#define KEYEVENT_H#include <QWidget>#include <QKeyEvent> //键盘#include <QPaintEvent> //绘画事件#include <QPainter>class KeyEvent : public QWidget{ Q_OBJECTpublic: KeyEvent(QWidget *parent = 0); ~KeyEvent(); void drawPix(); //绘画图像 void keyPressEvent(QKeyEvent *event); //键盘相应 void paintEvent(QPaintEvent *);private: QPixmap *pix; //缓冲图像 QImage image; //图片 int startX; int startY; int width; int height; int step; //每步的大小};#endif // KEYEVENT_H
keyevent.cpp
/*** 书本:【Qt5开发及实例】* 功能:实现键盘控制* 文件:keyevent.cpp* 时间:2015年2月8日11:48:47* 作者:cutter_point*/#include "keyevent.h"KeyEvent::KeyEvent(QWidget *parent) : QWidget(parent){ setWindowTitle(tr("键盘事件")); this->setAutoFillBackground(true); QPalette palette = this->palette(); //取得调色板 palette.setColor(QPalette::Window, Qt::white); //设置背景默认颜色 this->setPalette(palette); //设置好调色板，使用调色板 this->setMinimumSize(512, 256); this->setMaximumSize(512, 256); width = this->size().width(); height = this->size().height(); //得到相应的长和高 pix = new QPixmap(width, height);//缓冲图形的大小 pix->fill(Qt::white); image.load(":/image.png"); //加载图片 startX = 100; startY = 100; step = 20; drawPix(); //绘图 resize(512, 256);}//void drawPix(); //绘画图像void KeyEvent::drawPix(){ pix->fill(Qt::white); QPainter *painter = new QPainter; //绘画工具 QPen pen(Qt::DotLine);//虚线 for(int i = step; i < width; i = i + step) //画竖线{painter->begin(pix); //设定绘画对象painter->setPen(pen); //画笔painter->drawLine(QPoint(i, 0), QPoint(i, height)); //从一个点画到另外一个点painter->end();} //画横线 for(int j = step; j < height; j = j + step){painter->begin(pix);painter->setPen(pen);painter->drawLine(QPoint(0, j), QPoint(width, j));painter->end();} painter->begin(pix); painter->drawImage(QPoint(startX, startY), image); //图片绘制 painter->end();}//keyPressEvent(QKeyEvent *event); //键盘相应void KeyEvent::keyPressEvent(QKeyEvent *event){ if(event->modifiers() == Qt::ControlModifier) //是否有按下Ctrl{if(event->key() == Qt::Key_Left) //左{startX = (startX – 1 < 0) ? startX : startX – 1;}if(event->key() == Qt::Key_Right) //右{startX = (startX + image.width() > width) ? startX : startX + 1;}if(event->key() == Qt::Key_Up) //上{startY = (startY – 1 < 0) ? startY : startY – 1;}if(event->key() == Qt::Key_Down) //下{startY = (startY + image.height() > height) ? startY : startY + 1;}} else{startX = startX – startX % step;//化为step的倍数，，后面好判定startY = startY – startY % step;if(event->key() == Qt::Key_Left) //左{startX = (startX – step < 0) ? startX : startX – step;}if(event->key() == Qt::Key_Right) //右{startX = (startX + step + image.width() > width) ? startX : startX + step;}if(event->key() == Qt::Key_Up) //上{startY = (startY – step < 0) ? startY : startY – step;}if(event->key() == Qt::Key_Down) //下{startY = (startY + image.height() + step > height) ? startY : startY + step;}if(event->key() == Qt::Key_Home) //起点{startX = 0;startY = 0;}if(event->key() == Qt::Key_End) //终点{startX = width – image.width();startY = height – image.height();}} drawPix(); this->update();}//void paintEvent(QPaintEvent *);void KeyEvent::paintEvent(QPaintEvent *){ QPainter painter; painter.begin(this); painter.drawPixmap(QPoint(0, 0), *pix); //把图像画到空间，显示 painter.end();}KeyEvent::~KeyEvent(){}
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谁的指间滑过了千年时光；谁在反反复复中追问可曾遗忘；
