如何在QWidget中添加插槽？

Question

我有一個的QMainWindow，其具有QAction其信號triggered()被連接到狹槽about2() 。

...
connect(mAboutAction2, SIGNAL(triggered()), this, SLOT(about2()));
...


void occQt::about2()  //UI
{
    QWidget* pWidget = new QWidget;
    QPushButton* okbtn = new QPushButton(tr("ok"));
    QPushButton* cancelbtn = new QPushButton(tr("cancel"));
    btnlayout->addWidget(okbtn);
    btnlayout->addWidget(cancelbtn);
    dlglayout->setMargin(50);
    dlglayout->addLayout(gridlayout);
    dlglayout->addStretch(40);
    dlglayout->addLayout(btnlayout);
    pWidget->setLayout(dlglayout);
    pWidget->setWindowTitle(tr("Make a Box by custom."));
    pWidget->show();
    connect(okbtn, SIGNAL(clicked()), pWidget, SLOT(make_a_box()));
    connect(cancelbtn, SIGNAL(clicked()), pWidget, SLOT(close()));
}

void occQt::make_a_box()
{
    TopoDS_Shape aTopoBox = BRepPrimAPI_MakeBox(3.0, 4.0, 95.0).Shape();
    Handle_AIS_Shape anAisBox = new AIS_Shape(aTopoBox);

    anAisBox->SetColor(Quantity_NOC_AZURE);

    mContext->Display(anAisBox);
}

當我運行插槽about2() ，UI將打開。 單擊cancelbtn時可以將其關閉，但無法輸入插槽make_a_box() 。

在哪里可以添加此插槽以使此代碼正常工作？

Answer 1

沒關系，可以正常運行，因為您使用的插槽位於occQt類中的正確位置：。

// You connect the signal FROM the action TO "this", i.e. your class
connect(mAboutAction2, SIGNAL(triggered()), this, SLOT(about2()));

void occQt::about2()  //UI
{

    QWidget* pWidget = new QWidget;
    QPushButton* okbtn = new QPushButton(tr("ok"));
    QPushButton* cancelbtn = new QPushButton(tr("cancel"));
    btnlayout->addWidget(okbtn);
    btnlayout->addWidget(cancelbtn);
    dlglayout->setMargin(50);
    dlglayout->addLayout(gridlayout);
    dlglayout->addStretch(40);
    dlglayout->addLayout(btnlayout);
    pWidget->setLayout(dlglayout);
    pWidget->setWindowTitle(tr("Make a Box by custom."));
    pWidget->show();

現在，這不行：

 // You connect the signal FROM the button to pWidget, which doesn't have a slot make_a_box()
 connect(okbtn, SIGNAL(clicked()), pWidget, SLOT(make_a_box()));

槽make_a_box()不存在pWidget ，這是一個QWidget 。 您正在嘗試將信號連接到不存在的插槽。

您必須在occQt類中定義此插槽， 然后將按鈕的信號clicked()連接到類中的插槽 ：

// Now, you connect the signal FROM the button to "this", which is your class and has a slot make_a_box()
connect(okbtn, SIGNAL(clicked()), this, SLOT(make_a_box()));

在您的.h文件中，您將具有：

private slots : 
    void make_a_box();

在您的.cpp文件中：

void occQt::make_a_box()
{
    TopoDS_Shape aTopoBox = BRepPrimAPI_MakeBox(3.0, 4.0, 95.0).Shape();
    Handle_AIS_Shape anAisBox = new AIS_Shape(aTopoBox);

    anAisBox->SetColor(Quantity_NOC_AZURE);

    mContext->Display(anAisBox);
}