C ++ Qt信号和插槽不触发 [英] C++ Qt signal and slot not firing

问题描述

我在我的Qt程序有困难，连接按钮信号到我的插槽。我的代码是：

I am having difficulty in my Qt program with connecting button signals to my slots. My code is:

Main.cpp

#include <QtGui/QApplication>
#include "MainWidget.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    MainWidget mainWidget;
    mainWidget.show();

    return app.exec();
}

MainWidget.h

MainWidget.h

#ifndef MAINWIDGET_H
#define MAINWIDGET_H

#include <QWidget>

class MainWidget : public QWidget
{
public:
    MainWidget();

public slots:
    void bAdvice_clicked();
    void bWeather_clicked();
    void bNextMeeting_clicked();
    void bQuit_clicked();
};

#endif // MAINWIDGET_H

MainWidget.cpp

MainWidget.cpp

#include "MainWidget.h"
#include <QMessageBox>
#include <QPushButton>
#include <QTextEdit>
#include <QVBoxLayout>

MainWidget::MainWidget()
{
    QLayout *layout = new QVBoxLayout();
    this->setLayout(layout);

    QTextEdit *message = new QTextEdit();
    layout->addWidget(message);

    QPushButton *bAdvice = new QPushButton("Advice");
    connect(bAdvice, SIGNAL(clicked()), this, SLOT(bAdvice_clicked()));
    layout->addWidget(bAdvice);

    QPushButton *bWeather = new QPushButton("Weather");
    connect(bWeather, SIGNAL(clicked()), this, SLOT(bWeather_clicked()));
    layout->addWidget(bWeather);

    QPushButton *bNextMeeting = new QPushButton("Next Meeting");
    connect(bNextMeeting, SIGNAL(clicked()), this, SLOT(bNextMeeting_clicked()));
    layout->addWidget(bNextMeeting);

    QPushButton *bQuit = new QPushButton("Quit");
    connect(bQuit, SIGNAL(clicked()), this, SLOT(bQuit_clicked()));
    layout->addWidget(bQuit);
}

void MainWidget::bAdvice_clicked()
{
}

void MainWidget::bWeather_clicked()
{
}

void MainWidget::bNextMeeting_clicked()
{
    QMessageBox::information(this, "Next Meeting", "Today", QMessageBox::Ok);
}

void MainWidget::bQuit_clicked()
{
    this->close();
}

程序输出以下内容：

Starting C:\Users\Sameer\Documents\PartAQuestion2\debug\PartAQuestion2.exe...
Object::connect: No such slot QWidget::bAdvice_clicked() in MainWidget.cpp:16
Object::connect: No such slot QWidget::bWeather_clicked() in MainWidget.cpp:20
Object::connect: No such slot QWidget::bNextMeeting_clicked() in MainWidget.cpp:24
Object::connect: No such slot QWidget::bQuit_clicked() in MainWidget.cpp:28

C:\Users\Sameer\Documents\PartAQuestion2\debug\PartAQuestion2.exe exited with code 0

代码似乎是正确的，没有编译警告。只是这个输出在运行时。

The code seems right, no compiler warnings. Just this output at runtime. But it looks like I hooked the signals and slots up correctly.

推荐答案

添加 Q_OBJECT 到你的类，例如：

class MainWidget : public QWidget
{
    Q_OBJECT

您还必须运行moc来生成一些帮助程序代码。 qmake会自动为你做，但如果你自己编译，你需要运行moc。

You also have to run moc to generate some helper code. qmake does that automatically for your, but if you compile this yourself, you need to run moc.

这篇关于C ++ Qt信号和插槽不触发的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！