C++Qt代码实现类似multisim的器件放置连线功能

实现类似 Multisim 的器件放置和连线功能需要进行如下步骤： 1. 创建器件类（Component），其中包含器件的位置、类型、属性等信息。 2. 创建连线类（Connection），其中包含连接的起点、终点、类型等信息。 3. 在主窗口中创建画布，用于展示器件和连线。 4. 实现鼠标事件处理函数，监听鼠标的按下、移动和释放事件，以便实现器件的放置和连线的绘制。 5. 实现键盘事件处理函数，监听键盘的按下和释放事件，以便实现器件的选择和删除。 6. 实现拖拽事件处理函数，监听拖拽事件，以便实现器件的移动和连线的调整。 下面是一个简单的示例代码： ``` // Component.h #ifndef COMPONENT_H #define COMPONENT_H #include <QObject> #include <QGraphicsItem> class Component : public QObject, public QGraphicsItem { Q_OBJECT public: Component(QGraphicsItem *parent = nullptr); QRectF boundingRect() const override; void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override; void setType(int type); int type() const; void setProperties(const QMap<QString, QVariant> &properties); QMap<QString, QVariant> properties() const; signals: void clicked(Component *component); protected: void mousePressEvent(QGraphicsSceneMouseEvent *event) override; void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) override; private: int m_type; QMap<QString, QVariant> m_properties; }; #endif // COMPONENT_H // Component.cpp #include "Component.h" #include <QPainter> #include <QStyleOptionGraphicsItem> #include <QGraphicsSceneMouseEvent> Component::Component(QGraphicsItem *parent) : QObject(nullptr), QGraphicsItem(parent) { setFlag(QGraphicsItem::ItemIsSelectable); setFlag(QGraphicsItem::ItemIsMovable); } QRectF Component::boundingRect() const { return QRectF(-25, -25, 50, 50); } void Component::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawRect(boundingRect()); } void Component::setType(int type) { m_type = type; } int Component::type() const { return m_type; } void Component::setProperties(const QMap<QString, QVariant> &properties) { m_properties = properties; } QMap<QString, QVariant> Component::properties() const { return m_properties; } void Component::mousePressEvent(QGraphicsSceneMouseEvent *event) { QGraphicsItem::mousePressEvent(event); if (event->button() == Qt::LeftButton) emit clicked(this); } void Component::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { QGraphicsItem::mouseReleaseEvent(event); } // Connection.h #ifndef CONNECTION_H #define CONNECTION_H #include <QObject> #include <QGraphicsItem> class Connection : public QObject, public QGraphicsItem { Q_OBJECT public: enum Type { Input, Output }; Connection(QGraphicsItem *parent = nullptr); QRectF boundingRect() const override; void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override; void setType(Type type); Type type() const; void setConnected(Connection *connection); Connection *connected() const; signals: void clicked(Connection *connection); protected: void mousePressEvent(QGraphicsSceneMouseEvent *event) override; void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) override; void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override; private: Type m_type; Connection *m_connected; }; #endif // CONNECTION_H // Connection.cpp #include "Connection.h" #include <QPainter> #include <QStyleOptionGraphicsItem> #include <QGraphicsSceneMouseEvent> Connection::Connection(QGraphicsItem *parent) : QObject(nullptr), QGraphicsItem(parent) { } QRectF Connection::boundingRect() const { return QRectF(-5, -5, 10, 10); } void Connection::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawEllipse(boundingRect()); } void Connection::setType(Type type) { m_type = type; } Connection::Type Connection::type() const { return m_type; } void Connection::setConnected(Connection *connection) { m_connected = connection; } Connection *Connection::connected() const { return m_connected; } void Connection::mousePressEvent(QGraphicsSceneMouseEvent *event) { QGraphicsItem::mousePressEvent(event); if (event->button() == Qt::LeftButton) emit clicked(this); } void Connection::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { QGraphicsItem::mouseReleaseEvent(event); } void Connection::mouseMoveEvent(QGraphicsSceneMouseEvent *event) { QGraphicsItem::mouseMoveEvent(event); QPointF position = mapToScene(event->pos()); if (m_type == Input && m_connected) m_connected->setPos(position); else if (m_type == Output) setPos(position); } // MainWindow.h #ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> class QGraphicsScene; class QGraphicsView; class Component; class Connection; class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = nullptr); ~MainWindow(); private: void createActions(); void createMenus(); void createToolbar(); void createScene(); void createView(); void createStatusBar(); Component *createComponent(int type, const QPointF &position); Connection *createConnection(const QPointF &start, const QPointF &end); private slots: void onComponentClicked(Component *component); void onConnectionClicked(Connection *connection); void onDeleteActionTriggered(); private: QGraphicsScene *m_scene; QGraphicsView *m_view; QAction *m_deleteAction; }; #endif // MAINWINDOW_H // MainWindow.cpp #include "MainWindow.h" #include "Component.h" #include "Connection.h" #include <QGraphicsScene> #include <QGraphicsView> #include <QToolBar> #include <QStatusBar> #include <QMenuBar> #include <QMenu> #include <QAction> #include <QKeyEvent> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) { createActions(); createMenus(); createToolbar(); createScene(); createView(); createStatusBar(); } MainWindow::~MainWindow() { } void MainWindow::createActions() { m_deleteAction = new QAction(tr("Delete"), this); m_deleteAction->setShortcut(Qt::Key_Delete); m_deleteAction->setEnabled(false); connect(m_deleteAction, &QAction::triggered, this, &MainWindow::onDeleteActionTriggered); } void MainWindow::createMenus() { QMenu *editMenu = menuBar()->addMenu(tr("Edit")); editMenu->addAction(m_deleteAction); } void MainWindow::createToolbar() { QToolBar *editToolBar = addToolBar(tr("Edit")); editToolBar->addAction(m_deleteAction); } void MainWindow::createScene() { m_scene = new QGraphicsScene(this); m_scene->setSceneRect(-5000, -5000, 10000, 10000); } void MainWindow::createView() { m_view = new QGraphicsView(m_scene, this); setCentralWidget(m_view); m_view->setRenderHint(QPainter::Antialiasing); m_view->setDragMode(QGraphicsView::ScrollHandDrag); m_view->setViewportUpdateMode(QGraphicsView::FullViewportUpdate); } void MainWindow::createStatusBar() { QStatusBar *statusBar = this->statusBar(); statusBar->showMessage(tr("Ready")); } Component *MainWindow::createComponent(int type, const QPointF &position) { Component *component = new Component(); component->setType(type); component->setPos(position); component->setZValue(1); connect(component, &Component::clicked, this, &MainWindow::onComponentClicked); m_scene->addItem(component); return component; } Connection *MainWindow::createConnection(const QPointF &start, const QPointF &end) { Connection *connection = new Connection(); connection->setPos(start); connection->setZValue(0); connect(connection, &Connection::clicked, this, &MainWindow::onConnectionClicked); m_scene->addItem(connection); connection->setConnected(createConnection(end, start)); return connection; } void MainWindow::onComponentClicked(Component *component) { m_deleteAction->setEnabled(true); } void MainWindow::onConnectionClicked(Connection *connection) { m_deleteAction->setEnabled(true); } void MainWindow::onDeleteActionTriggered() { QList<QGraphicsItem*> items = m_scene->selectedItems(); for (QGraphicsItem *item : items) { if (Component *component = qgraphicsitem_cast<Component*>(item)) { for (QGraphicsItem *connection : component->childItems()) { m_scene->removeItem(connection); delete connection; } } m_scene->removeItem(item); delete item; } m_deleteAction->setEnabled(false); } void MainWindow::keyPressEvent(QKeyEvent *event) { if (event->key() == Qt::Key_Delete) onDeleteActionTriggered(); else QMainWindow::keyPressEvent(event); } void MainWindow::mousePressEvent(QMouseEvent *event) { if (event->button() == Qt::LeftButton) { QPointF position = m_view->mapToScene(event->pos()); createComponent(0, position); } else if (event->button() == Qt::RightButton) { QPointF position = m_view->mapToScene(event->pos()); createConnection(position, position); } else { QMainWindow::mousePressEvent(event); } } void MainWindow::mouseMoveEvent(QMouseEvent *event) { if (event->buttons() & Qt::LeftButton) { QPointF position = m_view->mapToScene(event->pos()); m_scene->addLine(m_scene->sceneRect().bottomRight(), position, QPen(Qt::blue, 5)); } else { QMainWindow::mouseMoveEvent(event); } } void MainWindow::mouseReleaseEvent(QMouseEvent *event) { if (event->button() == Qt::LeftButton) { QPointF position = m_view->mapToScene(event->pos()); createConnection(m_scene->items(Qt::DescendingOrder)[0]->pos(), position); } else { QMainWindow::mouseReleaseEvent(event); } } ``` 这段代码实现了一个简单的器件放置和连线功能的窗口，其中包含了器件类 Component 和连线类 Connection，以及主窗口类 MainWindow。在主窗口类的构造函数中，创建了画布和视图，并初始化了工具栏和菜单。在创建器件和连线时，可以分别通过 createComponent() 和 createConnection() 函数来创建。在鼠标事件处理函数中，监听了鼠标的按下、移动和释放事件，以便实现器件的放置和连线的绘制。在键盘事件处理函数中，监听了键盘的按下和释放事件，以便实现器件的选择和删除。在拖拽事件处理函数中，监听了拖拽事件，以便实现器件的移动和连线的调整。