如何将密钥事件发送到 QDialog 中的 qwidget

Question

我正在尝试创建一个返回双精度的对话框，类似于QInputDialog，但对话框中包含数字按钮。 它适用于没有键盘的嵌入式系统。

问题是QDoubleSpinBox从不对按键/释放做出反应。 对话框本身正在接收关键事件。 我尝试在keyPressEvent()和keyReleaseEvent()中调用event->ignore()，但没有成功。 还尝试调用QApplication：:p rocessEvents()，但没有成功。

我正在使用在嵌入式ARM处理器上运行的Qt 4.8。

NumericDialog.h

#ifndef NUMERICDIALOG_H
#define NUMERICDIALOG_H
#include <QDialog>
#include <QSignalMapper>
namespace Ui {
class NumericDialog;
}
class NumericDialog : public QDialog
{
Q_OBJECT
public:
explicit NumericDialog(QWidget *parent = 0);
~NumericDialog();
void keyPressEvent(QKeyEvent *event);
void keyReleaseEvent(QKeyEvent *event);
void SetMax(double max);
void SetMin(double min);
void SetValue(double value);
void SetSuffix(QString suffix);
void SetTrimEnable(bool enable);
private slots:
void ButtonClicked(int key);
private:
Ui::NumericDialog *ui;
QSignalMapper _SignalMapper;
};
#endif // NUMERICDIALOG_H

数字对话框.cpp

#include "NumericDialog.h"
#include "ui_NumericDialog.h"
#include <QKeyEvent>
#include <QDebug>

NumericDialog::NumericDialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::NumericDialog)
{
ui->setupUi(this);
this->setFocusPolicy(Qt::NoFocus);
ui->doubleSpinBox->setFocusPolicy(Qt::StrongFocus);
ui->doubleSpinBox->setFocus();
// Map signals, so we can use one slot for all buttons
_SignalMapper.setMapping(ui->button0, '0');
_SignalMapper.setMapping(ui->button1, '1');
_SignalMapper.setMapping(ui->button2, '2');
_SignalMapper.setMapping(ui->button3, '3');
_SignalMapper.setMapping(ui->button4, '4');
_SignalMapper.setMapping(ui->button5, '5');
_SignalMapper.setMapping(ui->button6, '6');
_SignalMapper.setMapping(ui->button7, '7');
_SignalMapper.setMapping(ui->button8, '8');
_SignalMapper.setMapping(ui->button9, '9');
_SignalMapper.setMapping(ui->buttonDot, '.');
_SignalMapper.setMapping(ui->buttonBS, Qt::Key_Backspace);
_SignalMapper.setMapping(ui->buttonEnter, Qt::Key_Enter);
_SignalMapper.setMapping(ui->buttonCancel, Qt::Key_Cancel);
_SignalMapper.setMapping(ui->buttonUp, Qt::Key_Up);
_SignalMapper.setMapping(ui->buttonDown, Qt::Key_Down);

connect(ui->button0, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button1, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button2, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button3, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button4, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button5, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button6, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button7, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button8, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->button9, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonDot, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonBS, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonEnter, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonCancel, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonUp, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(ui->buttonDown, SIGNAL(clicked()), &_SignalMapper, SLOT(map()));
connect(&_SignalMapper, SIGNAL(mapped(int)),this, SLOT(ButtonClicked(int)));

}
NumericDialog::~NumericDialog()
{
delete ui;
}
void NumericDialog::keyPressEvent(QKeyEvent *event)
{
qDebug() << "Dialog got key press" << event->text();
QDialog::keyPressEvent(event);
}
void NumericDialog::keyReleaseEvent(QKeyEvent *event)
{
qDebug() << "Dialog got key release" << event->text();
QDialog::keyReleaseEvent(event);
}
void NumericDialog::SetMax(double max)
{
ui->doubleSpinBox->setMaximum(max);
ui->labelMax->setText(QString("%1").arg(max));
ui->progressBar->setMaximum(max);
}
void NumericDialog::SetMin(double min)
{
ui->doubleSpinBox->setMinimum(min);
ui->labelMin->setText(QString("%1").arg(min));
ui->progressBar->setMinimum(min);
}
void NumericDialog::SetValue(double value)
{
ui->doubleSpinBox->setValue(value);
ui->progressBar->setValue(value);
}
void NumericDialog::SetSuffix(QString suffix)
{
ui->doubleSpinBox->setSuffix(suffix);
}
void NumericDialog::ButtonClicked(int key)
{
switch(key)
{
case Qt::Key_Enter:
break;
case Qt::Key_Cancel:
break;
case Qt::Key_Up:
break;
case Qt::Key_Down:
break;
default:
QKeyEvent keyPress(QEvent::KeyPress, key, Qt::NoModifier, QString(QChar(key)));
qDebug() << keyPress.text();
QApplication::sendEvent(ui->doubleSpinBox, &keyPress);
QKeyEvent keyRelease(QEvent::KeyRelease, key, Qt::NoModifier, QString(QChar(key)));
qDebug() << keyRelease.text();
QApplication::sendEvent(ui->doubleSpinBox, &keyRelease);
//QApplication::processEvents();
break;
}
}

当我单击数字"9"按钮时，控制台输出为：

"9"9">

对话框获得密钥释放"9">

当我单击退格键时，控制台输出为：

" " 对话框按键" " " " 对话框获得密钥释放" "

双旋转框中的值没有更改。 如何将关键事件获取到双旋转盒？

谢谢 玛丽

Answer 1

我必须将所有按钮的focusPolicy设置为NoFocus(在QtDesigner中)。它现在的行为符合预期。