QT简易画笔
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左键按住绘画,右键清空
#ifndef WIDGET_H #define WIDGET_H #include <QWidget> #include <QMouseEvent> #include <QKeyEvent> #include <QPaintEvent> #include <QPainter> #include <QPoint> #include <string> #include <list> QT_BEGIN_NAMESPACE namespace Ui { class Widget; } QT_END_NAMESPACE class Widget : public QWidget { Q_OBJECT class mesages{ public: int x; int y; QString msg; }; public: Widget(QWidget *parent = nullptr); ~Widget(); void mousePressEvent(QMouseEvent *) ; void keyPressEvent(QKeyEvent *) ; bool EventFilter(QObject *,QEvent *); void paintEvent(QPaintEvent *); QPainter *p; void getTex(); QList<mesages> mytextlist; void mouseMoveEvent(QMouseEvent *); private slots: void on_pushButton_clicked(); void on_widget_customContextMenuRequested(const QPoint &pos); private: Ui::Widget *ui; }; #endif // WIDGET_H
主要是鼠标事件绘图事件
#include "widget.h" #include "ui_widget.h" #include <QEvent> #include <qdebug.h> #include <string> Widget::Widget(QWidget *parent) : QWidget(parent) , ui(new Ui::Widget) { ui->setupUi(this); // connect(this,SIGNAL(returnPressed()),this,SLOT(on_pushButton_clicked())); ui->pushButton->installEventFilter(ui->pushButton); } Widget::~Widget() { delete ui; } void Widget::on_pushButton_clicked() { // QObject::connect() ui->textEdit1->clear(); // ui->textEdit1->changeEvent() ui->Ui_Widget::pushButton->setText("ssssss"); // this->close(); } void Widget::keyPressEvent(QKeyEvent *event) { int key=event->key(); qDebug()<<(char)key; if (event->key() == Qt::Key_Return && (event->modifiers() & Qt::ControlModifier)) { ui->textEdit1->clear(); ui->Ui_Widget::pushButton->setText("回车"); } } bool Widget::EventFilter(QObject *q,QEvent *e){ if(q==(QObject*)ui->pushButton&&((static_cast<QKeyEvent*>(e)->key() == Qt::Key_Return))){ return true; } return QWidget::eventFilter(q,e); } void Widget::paintEvent(QPaintEvent *) { QPainter painter(this); p = new QPainter(this); painter.drawText(QPoint(300,50),"this is my widget"); getTex(); // //绘制一行文字 // p = new QPainter(this); // p->drawText(QPoint(300,50),"this is my widget"); } void Widget::getTex(){ foreach (mesages msg, mytextlist) { p->drawText(QPoint(msg.x,msg.y),msg.msg); } p->renderHints(); this->update(); }; void Widget::mousePressEvent(QMouseEvent *ev) { if( ev->button()==Qt::LeftButton){ ui->textEdit1->clear(); ui->Ui_Widget::pushButton->setText("左键"); mesages msg; msg.x=ev->x(); msg.y=ev->y(); msg.msg="this is my 左键"; mytextlist.push_back(msg); }; if( ev->button()==Qt::RightButton){ ui->textEdit1->clear(); ui->Ui_Widget::pushButton->setText("右键"); mytextlist.clear(); if(ev->modifiers()==Qt::EnterKeyReturn){ ui->textEdit1->clear(); ui->Ui_Widget::pushButton->setText("回车"); } } } void Widget::mouseMoveEvent(QMouseEvent *ev){ // if( ev->button()==Qt::LeftButton){}; ui->textEdit1->clear(); ui->Ui_Widget::pushButton->setText("左键move"); mesages msg; msg.x=ev->x(); msg.y=ev->y(); msg.msg="this is my 左键move"; mytextlist.push_back(msg); }
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