Question

我正在尝试使用QAction（QMenu成员条目）打开一个新窗口。确切地说：我希望actionAbout信号预定义activated与MainWindow自定义广告位open AboutWindow匹配 - 这就是我遇到的麻烦。

我知道我可以在源main_window.cpp文件中手动使用connect Qt功能，或者只是在Qt Creator中单击它，但我的自定义插槽没有显示，所以我无法选择它。也许我的插槽函数声明是错误的（无效参数），这就是为什么QtCreator不允许我在GUI signals & slots中选择我的自定义插槽的原因。任何人都可以指出我应该怎样做才能让QtCreator在下拉列表中显示我的自定义插槽以及连接函数调用应该如何？

这是我的main_window.h文件内容：

#include 
#include "about_window.h"

namespace Ui {
    class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

public slots:
   void openAboutWindow();

private:
    Ui::MainWindow *ui;
    Ui::AboutWindow *aboutWindow;
};

这是main_window.cpp：

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    connect(actionAbout, SIGNAL(activated()), this, SLOT(openAboutWindow(this));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::openAboutWindow(QWidget *parent)
{
   aboutWindow = new Ui::AboutWindow(parent); // Be sure to destroy you window somewhere
   aboutWindow->show();
}

编译器对构造函数和openAbutWindow大声喊叫：

../Application/main_window.cpp: In constructor ‘MainWindow::MainWindow(QWidget*)’:
../Application/main_window.cpp:9:13: error: ‘actionAbout’ was not declared in this scope
../Application/main_window.cpp:9:80: error: expected ‘)’ before ‘;’ token
../Application/main_window.cpp: In member function ‘void MainWindow::openAboutWindow(QWidget*)’:
../Application/main_window.cpp:19:44: error: invalid use of incomplete type ‘struct Ui::AboutWindow’
../Application/about_window.h:7:11: error: forward declaration of ‘struct Ui::AboutWindow’
../Application/main_window.cpp:20:15: error: invalid use of incomplete type ‘struct Ui::AboutWindow’
../Application/about_window.h:7:11: error: forward declaration of ‘struct Ui::AboutWindow’

Answer 1

../Application/main_window.cpp:9:13: error: ‘actionAbout’ was not declared in this scope

错误消息说明了所有内容，QAction定义在哪里？它应该是ui->actionAbout吗？

connect(actionAbout, SIGNAL(activated()), this, SLOT(openAboutWindow(this));

openAboutWindow()不接受任何参数，无论this是不是类型的实例。

Qt匹配信号与自定义插槽

1 个答案: