Qt 中 mainwindow.h 中的类对象

Class object in mainwindow.h in Qt

本文关键字：对象 mainwindow Qt      更新时间：2023-10-16

每当单击主窗口上的按钮时，我都会打开一个新窗口(qt3d 应用程序中带有立方体视图的窗口(。

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "cubeview.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    int getid();
public slots:
    void pattern1();
private:
    CubeView *view;
    Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

和主窗口.cpp文件

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPushButton>
#include <iostream>
#include "cubeview.h"
int pattern_id;
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QPushButton *button= new QPushButton("Pattern 1");
    QObject::connect(button, SIGNAL(clicked()), this,  SLOT(pattern1()));
    button->show();
    std::cout<<"reached mainwindow constructor"<<std::endl;
    //view= new CubeView;
}
void MainWindow::pattern1()
{
    pattern_id=1;
    view->begin(1);
    view->resize(800, 600);
    view->show();
    std::cout<<pattern_id<<std::endl;
}
int MainWindow::getid()
{
    return pattern_id;
}
MainWindow::~MainWindow()
{
    delete ui;
    delete view;
}

我收到运行时错误。

我希望你明白我想做的事情。 每当我单击按钮时，都会显示立方体视图窗口。我犯了什么错误？我应该在哪里定义 cubeView 类对象，以便以后可以使用它。我可以将其初始化为立方体视图 *视图=新的立方体视图吗？在头文件中。我试图在主窗口的构造函数中编写它.cpp但是我收到运行时错误。

#ifndef CUBEVIEW_H
#define CUBEVIEW_H
#include "qglview.h"
#include "qgltexture2d.h"
QT_BEGIN_NAMESPACE
class QGLSceneNode;
QT_END_NAMESPACE
//! [1]
class CubeView : public QGLView
{
//! [1]
    Q_OBJECT
public:
    CubeView(QWidget *parent = 0);
    ~CubeView();
    void begin(int pattern_id);
public slots:
    void update_action();
protected:
    void paintGL(QGLPainter *painter);
    //! [2]
private:
    QGLSceneNode *cube;
    QGLSceneNode *cursor;
    QGLTexture2D logo;
    QGLTexture2D* texture;
    QGLTexture2D handcursor;
};
//! [2]
#endif

//! [1] constructor, initialize the cube, cursor and camera
CubeView::CubeView(QWidget *parent)
{
    //! [1] draw the paintboard
    QVector3D *cube1_pos= new QVector3D(0.0,0.0,-1.5);
    QGLBuilder builder1;
    builder1 << QGL::Faceted;
    builder1 << QGLCube(3.25);
    cube = builder1.finalizedSceneNode();
    cube->setPosition(*cube1_pos);
    //draw the cursor
    QGLBuilder cursor_builder;
    cursor_builder <<QGL::Faceted;
    cursor_builder <<QGLCube(0.15);
    cursor=cursor_builder.finalizedSceneNode();
    //camera setup
    camera()->setFieldOfView(35);
    camera()->setNearPlane(1);
    camera()->setFarPlane(15);
    //! [2] set texture for cube and cursor
    //QImage image(QLatin1String(":/bluecircle.jpg"));
    handcursor.setImage(QImage(QLatin1String(":/hand.jpg")));
    std::cout<<"constructor called"<<std::endl;

}
我想

我终于找到了答案。它与 cubeview 类构造函数的定义无关。简单的原理是->我们不需要在循环中创建类对象，否则程序代码崩溃。-> 如果直接放在连接槽内，view.show 也会遇到无限循环的错误。这是答案。

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPushButton>
#include <iostream>
#include "cubeview.h"
int pattern_id;
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    view=0;
    std::cout<<"reached mainwindow constructor"<<std::endl;
     QPushButton *button= new QPushButton("Pattern 1");
       QObject::connect(button, SIGNAL(clicked()), this,  SLOT(pattern1()));
       button->show();
   else if(view!=NULL)
    {
        std::cout<<"view is already initialized"<<std::endl;
    }
}
void MainWindow::pattern1()
{
  if(view==NULL)
    {
        view=new CubeView;
        view->begin(1);
        view->resize(800, 600);
            view->show();
    }
}
int MainWindow::getid()
{
    return pattern_id;
}
MainWindow::~MainWindow()
{
    delete ui;
        delete view;
}

这样，如果值已为 NULL，则会创建新的对象窗口。

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