Qgraphicsview How to add and change picture Size! __qgraphicview

1 Create engineering Scale, base class for Qwidget, use layout layout, engineering files for main.cpp widget.h widget.cpp

A Add 2 button controls ZoomIn and Zoomout.

b Add Control Qgraphicsview.

C Signal for clicked

2 widget.h.

#include <QtCore>

#include <QtGui>

#include <QGraphicsItem>

#include <QGraphicsView>

#include <QWidget>

Private

    Qreal num;

    QString filename;

    Qpixmap Pixmap;

    Qgraphicsitem *item;

    Qgraphicsscene *scene;

Class in the constructor of the 3 widget.cpp.

    num=0;  Size scale

    Scene = new Qgraphicsscene (this);

    Ui->graphicsview->setscene (Scene);

    Pixmap.load (filename);

    Filename= "1.jpg";

    Item=scene->addpixmap (PIXMAP);

    Item->setflag (qgraphicsitem::itemismovable);

    Item->setscale (0.1); Default Load Scale

In the CAO function of the 4 widget.cpp

void Widget::on_zoomin_clicked ()

{

    num=num+0.1;

    Item->setscale (num);

    Qdebug ("num +:%d", num);

}

void Widget::on_zoomout_clicked ()

{

    num=num-0.1;

    Item->setscale (num-0.1);

    Qdebug ("Num 1:%d", num);

}

Click on the button will be the picture larger or smaller, pay attention to num value, not less than 0;

		To be Continued ...