1. C/C++初学者的困惑
很多C/C++初学者，自学了很多年，考了很多证，开发水平仍停留在控制台小项目上，就业更是遥遥无期，进退两难。
C/C++的最强大的地方，当然是开发高性能框架、高性能服务器：
基于C++框架Tenserflow实现的阿尔法狗：
千万级并发服务器Nginx：
在问鼎C/C++技术之巅之前，有没有一个技术方向，让C/C++小白就能够快速高薪就业的呢？
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小白高薪研发的最佳方向，莫不过于C++ Qt开发，已经广泛应用于物联网、嵌入式、音视频、图形处理！
来自研发一线的岗位召唤：
让我们从零起步，90分钟开发一个Qt版的贪食蛇，快速掌握C++ Qt开发！
【视频教程：https://www.bilibili.com/video/BV1aa4y1v7PK】
1. 创建项目
选择模板
选择编译器：
准备游戏素材
添加数据成员
enum Direct{Left,Right,Up,Down};
QList<QRectF> snake;//贪吃蛇本体
int snakeNodeWidth = 20;
int snakeNodeHeight = 20;
QTimer *timer;
int time = 150;
int moveFlage = Up;
bool gameStart = false;
QRectF rewardNode;
添加方法的声明
protected:
void paintEvent(QPaintEvent *);
void keyPressEvent(QKeyEvent *);
void addTop();
void addDown();
void addLeft();
void addRight();
void deleteLast();
bool checkContact();
void addNewReward();添加槽函数
protected slots:
void timeOut();构造函数
#include <QTimer>
Widget::Widget(QWidget *parent)
: QWidget(parent)
, ui(new Ui::Widget)
{
ui->setupUi(this);
resize(600, 368);
snake.append(QRectF(300,180,snakeNodeWidth,snakeNodeHeight));
addTop();
addTop();
timer = new QTimer;
connect(timer, SIGNAL(timeout()),this,SLOT(timeOut()));
addNewReward();
}按键时间处理
#include <QKeyEvent>
void Widget::keyPressEvent(QKeyEvent *event)
{
switch(event->key()){
case Qt::Key_Up:
if(moveFlage != Down){
moveFlage = Up;
}
break;
case Qt::Key_Down:
if(moveFlage != Up){
moveFlage = Down;
}
break;
case Qt::Key_Right:
if(moveFlage != Left){
moveFlage = Right;
}
break;
case Qt::Key_Left:
if(moveFlage != Right){
moveFlage = Left;
}
break;
case Qt::Key_Space:
if(!gameStart){
timer->start(time);
gameStart = true;
}else {
timer->stop();
gameStart = false;
}
break;
default:
break;
}
}超时事件处理
void Widget::timeOut()
{
int count = 1;
if (snake.at(0).intersects(rewardNode)) {
addNewReward();
count++;
}
while (count--) {
switch (moveFlage) {
case Up:
addTop();
break;
case Down:
addDown();
break;
case Right:
addRight();
break;
case Left:
addLeft();
break;
default:
break;
}
}
deleteLast();
update();
}添加新方块
void Widget::addNewReward() {
rewardNode = QRectF(
qrand()%(this->width()/20)*20,
qrand()%(this->height()/20)*20,
snakeNodeWidth,
snakeNodeWidth);
}各个方向的运动实现
//向上移动
void Widget::addTop()
{
QPointF leftTop;
QPointF rightBotom;
if(snake.at(0).y()-snakeNodeHeight < 0){
leftTop = QPointF(
snake.at(0).x(), //左上角x坐标
this->height()-snakeNodeHeight); //左上角y坐标
rightBotom = QPointF(
snake.at(0).x()+snakeNodeWidth,
this->height());
}else{
leftTop = QPointF(snake.at(0).x(),
snake.at(0).y() - snakeNodeHeight);
rightBotom = snake.at(0).topRight();
}
snake.insert(0, QRectF(leftTop, rightBotom));
}
//向下移动
void Widget::addDown()
{
QPointF leftTop;
QPointF rightBotom;
if(snake.at(0).y()+snakeNodeHeight*2 > this->height()){
leftTop = QPointF(snake.at(0).x(), 0);
rightBotom = QPointF(snake.at(0).x()+snakeNodeWidth, snakeNodeHeight);
}else{
leftTop = snake.at(0).bottomLeft();
rightBotom = snake.at(0).bottomRight() + QPointF(0, snakeNodeHeight);
}
snake.insert(0, QRectF(leftTop, rightBotom));
}
//向左移动
void Widget::addLeft()
{
QPointF leftTop;
QPointF rightBotom;
if(snake.at(0).x()-snakeNodeWidth < 0){
leftTop = QPointF(this->width() -snakeNodeWidth, snake[0].y());
}else{
leftTop = snake[0].topLeft() - QPointF(snakeNodeWidth, 0);
}
rightBotom = leftTop + QPointF(snakeNodeWidth, snakeNodeHeight);
snake.insert(0, QRectF(leftTop, rightBotom));
}
//向右移动
void Widget::addRight()
{
QPointF leftTop;
QPointF rightBotom;
if(snake.at(0).x()+snakeNodeWidth*2 > this->width()){
leftTop = QPointF(0, snake[0].y());
}else{
leftTop = snake[0].topRight();
}
rightBotom = leftTop + QPointF(snakeNodeWidth, snakeNodeHeight);
snake.insert(0, QRectF(leftTop, rightBotom));
}
//删除结尾数据
void Widget::deleteLast()
{
snake.removeLast();
}绘制贪食蛇
#include <QPainter>
#include <QPen>
#include <QBrush>
void Widget::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
QPen pen; //画笔，用于绘制轮廓
QBrush brush; //画刷，用于填充
QPixmap pix;
pix.load("D:/tmp/snake.jpg");
painter.drawPixmap(0,0, 600, 368,pix);
//反锯齿
painter.setRenderHint(QPainter::Antialiasing);
pen.setColor(Qt::black);
brush.setColor(Qt::darkMagenta);
brush.setStyle(Qt::SolidPattern);
painter.setPen(pen);
painter.setBrush(brush);
for(int i=0; i<snake.length(); i++){
painter.drawRect(snake.at(i));
}
brush.setColor(Qt::red);
painter.setBrush(brush);
painter.drawEllipse(rewardNode);
pen.setColor(Qt::black);
painter.setPen(pen);
QFont font("微软雅黑", 12,QFont::ExtraLight,false);
painter.setFont(font);
painter.drawText(560, 32, QString("%1").arg(snake.length()));
if(checkContact()){
QFont font("方正舒体",30,QFont::ExtraLight,false);
painter.setFont(font);
painter.drawText((this->width()-300)/2,(this->height()-30)/2,QString("GAME OVER!"));
timer->stop();
}
QWidget::paintEvent(event);
}失败检测
//判断蛇头是否和蛇身相撞, 以及蛇身和蛇身相撞
bool Widget::checkContact()
{
for(int i=0; i<snake.length();i++) {
for(int j=i+1; j<snake.length(); j++){
if(snake.at(i) == snake.at(j)){
return true;
}
}
}
return false;
}