Qt ⼀个简易画板的实现(Graphics View)

Qt 学习之路(32): ⼀个简易画板的实现(Graphics View)

这⼀次将介绍如何使⽤ Graphics View 来实现前⾯所说的画板。前⾯说了很多有关

Graphics View的好话，但是 有具体的实例很难说究竟好在哪⾥。现在我们就把前⾯

的内容使⽤ Graphics View 重新实现⼀下，⼤家可以对⽐⼀下看有什么区别。

同前⾯相似的内容就不再叙述了，我们从上次代码的基础上进⾏修改，以便符合我们

的需要。⾸先来看MainWindow 的代码：

mainwindow .cpp

#include "mainwindow .h"

MainWindow ::MainWindow(QWidget *parent)

: QMainWindow(parent)

{

QToolBar *bar this->addToolBar("Tools");

QActionGroup *group new QActionGroup(bar);

QAction *drawLineAction new QAction("Line", bar);

drawLineAction->setIcon(QIcon(":/line.png"));

drawLineAction->setToolTip(tr("Draw a line."));

drawLineAction->setStatusTip(tr("Draw a line."));

drawLineAction->setCheckable(true);

drawLineAction->setChecked(true);

group->addAction(drawLineAction);

bar->addAction(drawLineAction);

QAction *drawRectAction new QAction("Rectangle", bar);

drawRectAction->setIcon(QIcon(":/rect.png"));

drawRectAction->setToolTip(tr("Draw a rectangle."));

drawRectAction->setStatusTip(tr("Draw a rectangle."));

drawRectAction->setCheckable(true);

group->addAction(drawRectAction);

bar->addAction(drawRectAction);

QLabel *statusMsg new QLabel;

statusBar()->addWidget(statusMsg);

PaintWidget *paintWidget new PaintWidget(this);

QGraphicsView *view new QGraphicsView(paintWidget, this

setCentralWidget(view);

connect(drawLineAction, SIGNAL(triggered()),

this, SLOT(drawLineActionTriggered()));

connect(drawRectAction, SIGNAL(triggered()),

this, SLOT(drawRectActionTriggered()));

connect(this, SIGNAL(changeCurrentShape(Shape::Code)),

paintWidget, SLOT(setCurrentShape(Shape::

}

void MainWindow ::drawLineAc