我有一个带有相关菜单的工具按钮。
m_mainMenuButton = new ToolButton("menu.png", tr("Open menu"));
m_mainMenuButton->setMenu(m_mainMenu);
m_mainMenuButton->setPopupMode(QToolButton::InstantPopup);
我希望在用户按下并释放Alt时显示此菜单。这样,普通的QMenuBar
就可以在Windows上被激活(我想使用此工具按钮代替QMenuBar
)。我尝试过:
m_mainMenuButton->setShortcut(QKeySequence(Qt::Key_Alt));
,但在按下并释放Alt时不显示菜单。或这样:
auto shortcut = new QShortcut(QKeySequence(Qt::Key_Alt), this);
connect(shortcut, &QShortcut::activated, m_mainMenuButton, &QToolButton::showMenu);
它什么也没做。我尝试覆盖按键按下和释放事件,但随后发现它干扰了其他将按键Alt用作修饰符的按键快捷方式,例如“ Alt +左键”。
任何想法如何做到这一点?
更新一个最小的示例,该示例显示Alt不能用作快捷方式。
#include <QAction>
#include <QApplication>
#include <QLabel>
#include <QMainWindow>
#include <QMenu>
#include <QShortcut>
#include <QToolButton>
#include <QVBoxLayout>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QMainWindow w;
auto label = new QLabel();
auto menu = new QMenu(&w);
// intentionally added a shortcut which contains Alt as modifier to test it does not interfere with the menu
menu->addAction("Action", [label]{ label->setText("Trigered!"); }, QKeySequence("Alt+Left"));
auto btn = new QToolButton();
btn->setMenu(menu);
btn->setPopupMode(QToolButton::InstantPopup);
// the following lines do not have any effect, the menu is not shown when Alt is pressed and released
auto shortcut = new QShortcut(QKeySequence(Qt::Key_Alt), &w);
QObject::connect(shortcut, &QShortcut::activated, btn, &QToolButton::showMenu);
auto container = new QWidget();
auto layout = new QVBoxLayout(container);
layout->addWidget(btn);
layout->addWidget(label);
w.setCentralWidget(container);
w.show();
return a.exec();
}
答案 0 :(得分:0)
尝试使用QObject :: installEventFilter
(QObject :: eventFilter(obj,event))。
例如
QtStackOverflow.h
#pragma once
#include <QtWidgets/QMainWindow>
#include <QToolButton>
#include "ui_QtStackOverflow.h"
class QtStackOverflow : public QMainWindow
{
Q_OBJECT
public:
QtStackOverflow(QWidget *parent = Q_NULLPTR);
private:
Ui::QtStackOverflowClass ui;
};
class KeyPressEater : public QObject
{
Q_OBJECT
public:
KeyPressEater(QToolButton*btn) : keyOtherPush(false), keyAltPush(false) { _btn = btn; }
protected:
bool eventFilter(QObject *obj, QEvent *event);
private:
QToolButton * _btn;
bool keyOtherPush;
bool keyAltPush;
};
main.cpp
#include "QtStackOverflow.h"
#include <QtWidgets/QApplication>
#include <QObject>
#include <QEvent>
#include <QKeyEvent>
#include <QLabel>
#include <QMainWindow>
#include <QMenu>
#include <QShortcut>
#include <QToolButton>
#include <QVBoxLayout>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QMainWindow w;
auto label = new QLabel();
auto menu = new QMenu(&w);
// intentionally added a shortcut which contains Alt as modifier to test it does not interfere with the menu
int number = 0;
menu->addAction("Action", [label, &number] {
label->setText(QString("%1 %2 ").arg("Trigered!").arg(number));
number++;
}, QKeySequence("Alt+Left"));
auto btn = new QToolButton();
btn->setMenu(menu);
btn->setPopupMode(QToolButton::InstantPopup);
// the following lines do not have any effect, the menu is not shown when Alt is pressed and released
auto shortcut = new QShortcut(QKeySequence(Qt::Key_Alt), &w);
QObject::connect(shortcut, &QShortcut::activated, btn, &QToolButton::showMenu);
KeyPressEater *m_keyPressEater;
m_keyPressEater = new KeyPressEater(btn);
qApp->installEventFilter(m_keyPressEater);
auto container = new QWidget();
auto layout = new QVBoxLayout(container);
layout->addWidget(btn);
layout->addWidget(label);
w.setCentralWidget(container);
w.show();
return a.exec();
}
bool KeyPressEater::eventFilter(QObject *obj, QEvent *event)
{
if (event->type() == QEvent::KeyPress)
{
int key = static_cast<QKeyEvent *>(event)->key();
if (key == Qt::Key_Alt)
{
keyAltPush = true;
}
else {
keyOtherPush = true;
}
return QObject::eventFilter(obj, event);
}
else if (event->type() == QEvent::KeyRelease)
{
int key = static_cast<QKeyEvent *>(event)->key();
if (key == Qt::Key_Alt) {
if (keyAltPush == true && keyOtherPush == false) {
_btn->showMenu();
}
}
else {
keyAltPush = false;
keyOtherPush = false;
}
return true;
}
else {
return QObject::eventFilter(obj, event);
}
}
在这种情况下,您可以随时获得所有按键。
然后您需要检查QObject * senderObj = sender()
答案 1 :(得分:0)
这是受QMenuBar中的Qt实现启发的版本:
[A > b for b in B]
[array([ True, False, True, True], dtype=bool),
array([False, False, False, True], dtype=bool)]
Alt-Left快捷键可以正常工作,并且按钮菜单由Alt-Pres-Release切换。