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QT5 视图坐标

2024-07-10 22:52:36   223人阅读

又出错了。。

main.obj:-1: error: LNK2001: 无法解析的外部符号 "public: virtual struct QMetaObject const * __thiscall MyView::metaObject(void)const " (?metaObject@MyView@@UBEPBUQMetaObject@@XZ)

main.obj:-1: error: LNK2001: 无法解析的外部符号 "public: virtual void * __thiscall MyView::qt_metacast(char const *)" (?qt_metacast@MyView@@UAEPAXPBD@Z)

main.obj:-1: error: LNK2001: 无法解析的外部符号 "public: virtual int __thiscall MyView::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@MyView@@UAEHW4Call@QMetaObject@@HPAPAX@Z)

debug\myScene.exe:-1: error: LNK1120: 3 个无法解析的外部命令

这些错都是什么啊。。

我建立了一个继承自QWidget的类，基类是 QGraphicsView

然后生成了myview.h  自动加上了宏Q_OBJECT 所以就报那些错了。。 原理不懂呀

改完之后，记得清理项目！

myview.h

#ifndef MYVIEW_H
#define MYVIEW_H

#include <QGraphicsView>

class MyView : public QGraphicsView
{
   // Q_OBJECT  只需把这里注释掉就行了
public:
    explicit MyView(QWidget *parent = 0);
protected:
    void mousePressEvent(QMouseEvent *event);

signals:

public slots:

};

#endif // MYVIEW_H

myview.cpp

#include "myview.h"
#include <QMouseEvent>
#include <QGraphicsItem>
#include <QDebug>
MyView::MyView(QWidget *parent) :
    QGraphicsView(parent)
{
}
void MyView::mousePressEvent(QMouseEvent *event)
{
    QPoint viewPos = event->pos();
    qDebug() <<"viewPos:" << viewPos;
    QPointF scenePos = mapToScene(viewPos);
    qDebug() << "scenePos:" << scenePos;
    QTransform transform;
    QGraphicsItem *item = scene()->itemAt(scenePos,transform);
    if(item)
    {
        QPointF itemPos = item->mapFromScene(scenePos);
        qDebug() << "itemPos:" << itemPos;
    }
}

main.cpp

#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsRectItem>
#include <QGraphicsItem>
#include <QDebug>
#include <QGraphicsView>
#include "myitem.h"
#include "myitem.cpp"
#include "myview.h"
#include "myview.cpp"
int main(int argc,char *argv[])
{
    QApplication app(argc,argv);
    QGraphicsScene scene;
  //  QGraphicsRectItem * item = new QGraphicsRectItem(0,0,100,100);


    MyItem *item = new MyItem;
    scene.addItem(item);

    item->setPos(10,10);
    QGraphicsRectItem *rectItem = scene.addRect(QRect(0,0,100,100),
                                                QPen(Qt::blue),QBrush(Qt::green));
    rectItem->setPos(20,20);
    MyView view;
    view.setScene(&scene);
    view.setForegroundBrush(QColor(255,255,255,100));
    view.setBackgroundBrush(QPixmap("../myScene/11.jpg"));
    view.show();
    return app.exec();
}



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