QT实现画板源代码（雏形）

#include "widget.h" #include "ui_widget.h" #include "qpainter.h" #include "QMessageBox" #include "QDebug" Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { setMouseTracking(true); setPalette(QPalette(Qt::white)); pix = new QPixmap(size()); pix->fill(Qt::white); setMinimumSize(600,400); //设置窗体最小大小 color=Qt::black; weight=2; style=1; ui->setupUi(this); } Widget::~Widget() { delete ui; } void Widget::paintEvent(QPaintEvent *event) { QPainter painters(this); QRect rect(this->width()-140,this->height()-20,200,40); painters.drawText(rect,"mousePosition:"+QString::number(coursePoint.x())+","+QString::number(coursePoint.y())); // if(plist.count()>2) // for(int i=0;i<plist.count()-1;i++) // { // qDebug()<<i; // if(isEndPoint[i]>0) // painters.drawLine(plist[i],plist[1+i]); // } painters.drawPixmap(QPoint(0,0), *pix); } void Widget::mousePressEvent(QMouseEvent *event) { // QMessageBox::about(this,"title","hello"); startPos = event->pos(); start=true; } void Widget::mouseMoveEvent(QMouseEvent *event) { QPainter *painter = new QPainter; if(start) { painter->begin(pix); painter->drawLine(startPos, event->pos()); painter->end(); // plist.append(startPos); //isEndPoint.append(true); startPos =event->pos(); } coursePoint =event->pos();// QCursor::pos(); this->update(); } void Widget::mouseReleaseEvent(QMouseEvent *event) { //plist.append(startPos); //isEndPoint.append(false); start=false; }