Qt，两个QWidget对象之间的简单连接

Posted 2023-02-17

【中文标题】Qt，两个QWidget对象之间的简单连接

【英文标题】：Qt, a simple connection between two QWidget objects

【发布时间】：2013-02-27 12:04:42

【问题描述】：

我有一个继承自 QMainWindow 的类和两个继承自 QWidget 的类。我将这两个 QWidget 对象添加到我的 QMainWindow 对象中，并且我想在这两个 QWidget 对象之间创建一个连接（其中一个包含 QPushButton 对象）。不幸的是，不想工作......

代码：

主机：

#ifndef MAINFRAME_H
#define MAINFRAME_H

#include <QtGui/QMainWindow>
#include "DrawComponent.h"
#include "ControllComponent.h"

class MainFrame : public QMainWindow

    Q_OBJECT

public:
    DrawComponent *dComponent;
    ControllComponent *cComponent;
    MainFrame();

;

#endif 

#include "MainFrame.h"
#include "DrawComponent.h"
#include "ControllComponent.h"
#include <iostream>

using namespace std;

MainFrame :: MainFrame()
   
    this->setGeometry(100, 100, 640, 480);

    this->dComponent = new DrawComponent(this);
    this->cComponent = new ControllComponent(this); 

    QObject::connect(this->cComponent->rysuj1, SIGNAL(clicked()), this, SLOT(dComponent->draw1));

FIRST QWidget 类

#ifndef DRAWCOMPONENT_H
#define DRAWCOMPONENT_H

#include <QtGui/QMainWindow>
#include <qwidget.h>

class DrawComponent : public QWidget

    Q_OBJECT

public:
    DrawComponent(QMainWindow *parent);

public slots:
    void draw1();

;

#endif 

#include "DrawComponent.h"
#include <qpushbutton.h>
#include <qgridlayout.h>

using namespace std;

DrawComponent :: DrawComponent(QMainWindow *parent)

    this->setParent(parent);
    this->setGeometry(0, 0, 500, 480);

    QPalette p(palette());
    p.setColor(QPalette::Background, Qt::black);

    this->setPalette(p);
    this->setAutoFillBackground(true);
    this->show();


void DrawComponent :: draw1()

    QPalette p(palette());
    p.setColor(QPalette::Background, Qt::blue);

    this->setPalette(p);

第二个 QWidget 类

#ifndef CONTROLLCOMPONENT_H
#define CONTROLLCOMPONENT_H

#include <QtGui/QMainWindow>
#include <qwidget.h>
#include <qpushbutton.h>

class ControllComponent : public QWidget

    Q_OBJECT

public:
    QPushButton *rysuj1;
    ControllComponent(QMainWindow *parent);

;

#endif 

#include "ControllComponent.h"
#include <qpushbutton.h>
#include <qgridlayout.h>

ControllComponent :: ControllComponent(QMainWindow *parent)

    this->setParent(parent);
    this->setGeometry(500, 0, 140, 480);

    QPalette p(palette());
    p.setColor(QPalette::Background, Qt::red);
    this->setPalette(p);
    this->setAutoFillBackground(true);

    this->rysuj1 = new QPushButton(tr("draw1"), this);
    this->rysuj1->setGeometry(45, 10, 50, 50);
    this->rysuj1->show();

    this->show();

【参考方案1】：

您调用将来自rysuj1 的clicked() 信号连接到dComponent 的draw1() 插槽

QObject::connect(this->cComponent->rysuj1, SIGNAL(clicked()), 
                 this, SLOT(dComponent->draw1));

需要

QObject::connect(this->cComponent->rysuj1, SIGNAL(clicked()), 
                 dComponent, SLOT(draw1()));

【参考方案2】：

dComponent->draw1 

不是槽

看这里：

QObject::connect(&a, SIGNAL(valueChanged(int)),
                  &b, SLOT(setValue(int)));

参数：1. 对象，2. 信号函数，3. 对象，4. 槽函数。

所以

QObject::connect(this->cComponent->rysuj1, SIGNAL(clicked()), dComponent, SLOT(draw1()));