用枚举填充 QMenu

Question

我有一些 struct 带有 enum 和 std::string，我过去常常使用 for() 循环填充 QComboBox。像这样：

struct Struct
{
    enum Enum
    {
        ENTRY1,
        ENTRY2,
        ...
        ENTRY_ALL
    };
    std::string names[ENTRY_ALL] {...};
};
for(int i=0; i<Struct::ENTRY_ALL; ++i)
    comboBox->insertItem(i, names[i].c_str());

它有效，但考虑到最近的进展，我需要更多条目、更多 struct、更多组合框，而且它变得丑陋，所以我决定切换到 QMenu。

查看文档和示例，我看到我必须为每个条目提供一个 connect()，为每个条目提供一个 QAction，等等，如果我的 enums很大，这会成为一个问题，所以我想知道是否有办法自动执行此过程。

我的问题主要来自于为什么每个 QComboBox 我只需要一个 connect() 以及 QComboBox 如何知道，如果我填满它们，哪个条目会做什么？

如果有帮助的话，这是我所拥有的一些伪造代码：

// tank class, header:
class Class
{
private:
    // main entries
    struct MainStruct
    {
        enum Enum {MAIN1, MAIN2, MAIN3, MAIN_ALL};
        std::string names[MAIN_ALL] {"Main 1", "Main 2", "Main 3"};
    };
    // secondary entries
    struct SubStruct
    {
        enum Enum {SUB1, SUB2, SUB3, SUB_ALL};
        std::string names[SUB_ALL] {"Sub 1", "Sub 2", "Sub 3"};
    };
    // family of entries for SUB2
    struct FamStruct
    {
        enum Enum {FAM1, FAM2, FAM3, FAM_ALL};
        std::string names[FAM_ALL] {"Fam 1", "Fam 2", "Fam 3"};
    }
public:
    MainStruct mainEntries;
    SubStruct subEntries;
    FamStruct famEntries;
};

// inside the main window, there was a QComboBox doing this:
// header
QComboBox *cbMain, *cbSub, *cbFam;
// source
Class cls {Class()};
cbMain = new QComboBox; // same for cbSub, cbFam
// retranslateUi() (manually edited, not automatic), called each time the menu was clicked
void MainApp::retranslateUi()
{
    cbMain.clear();
    for(unsigned char i=0; i<cls.mainEntries.MAIN_ALL; ++i)
    {
        cbMain->insertItem(i, tr(cls.mainEntries.names[i].c_str()) );
        cbMain->setItemData(i, tr(cls.mainEntries.tooltips[i].c_str()), Qt::ToolTipRole);
    }
    // same for cbSub, cbFam
}
// a function that did what was supposed to do when a combo box entry was clicked
void MainApp::func() { /* execution with variables changed by the combo */ }
/* There were additional functions taking care of the rest.
 * Whenever an entry from the combo was clicked, somehow it "knew" that the entry was
 * changed and func(), when executed, it ran with the variables changed by combo.
 */
void MainApp::updateSub()
{
    switch(cbMain->currentIndex())
    {
    case cls.mainEntries.MAIN1: /*subentry stuff*/ break;
    case cls.mainEntries.MAIN2: /*subentry stuff*/ break;
    case cls.mainEntries.MAIN3: /*subentry stuff*/ break;
    }
}
void MainApp::updateFam()
{
    switch(cbSub->currentIndex())
    {
    case cls.subEntries.SUB1: /*fam entry stuff*/ break;
    case cls.subEntries.SUB2: /*fam entry stuff*/ break;
    case cls.subEntries.SUB3: /*fam entry stuff*/ break;
    }
}
/* The connect() were attached to specific combos. When an entry in cbMain was
 * clicked, cbSub and cbFam were properly updated and func() was run with
 * the proper values, when cbSub was clicked, cbFam was updated and func()
 * was run accordingly. Similar to an instant refresh.
 */
connect(cbMain, SIGNAL(activated(int)), this, SLOT(retranslateUi()));
connect(cbMain, SIGNAL(activated(int)), this, SLOT(updateSub()));
connect(cbMain, SIGNAL(activated(int)), this, SLOT(func()));
connect(cbSub, SIGNAL(activated(int)), this, SLOT(updateFam()));
connect(cbSub, SIGNAL(activated(int)), this, SLOT(func()));
connect(cbFam, SIGNAL(activated(int)), this, SLOT(func()));

每当我不得不为子菜单添加新的条目系列，甚至是带有子条目的主菜单时，事情都会变得复杂，所以我认为这样的菜单：

Menu:   Submenu:                AnotherSubmenu:
menu 1  submenu 1               altsub 1
menu 2  submenu 2 > family 1    altsub 2
menu 3  submenu 3   family 2    ...
                    family 3

会工作得更好，东西更整洁。 Menu 中的条目调用适当的 Submenu，它有自己的 Family，无论它们在哪里，Submenu 都可以调用另一个级别的 AnotherSubmenu，等等。

Answer 1

您可以将所有 QAction 的触发信号连接到同一个插槽，并能够使用 sender() 获得对象，并将其转换为 QAction 对象类型qobject_cast<>.

此外，如果您想使用索引，我们可以使用 setObjectName() 和 objectName()

void {your Widget}::createAction()
    QMenu *menu = new QMenu(this);
    for(int i=0; i < 10; ++i){
        QAction *action = new QAction(QString("action %1").arg(i));
        action->setObjectName(QString("%1").arg(i));
        connect(action, &QAction::triggered, this, &{your Widget}::onTriggeredAction);
        menu->addAction(action);
    }
}

void {your Widget}::onTriggeredAction()
{
    QAction *obj = qobject_cast<QAction *>(sender());
    int index = obj->objectName().toInt();
    qDebug()<<index;
}

用枚举填充 QMenu

Fill QMenu with an enum

c++

qt

enums

qmenu