void Form1::keyPressEvent( QKeyEvent *k )
{
if(k->key() == Key_A)
{
this->focusNextPrevChild(FALSE);//按A时焦点切换至上一部件
}
else if(k->key() == Key_D)
{
this->focusNextPrevChild(TRUE);//按D时焦点切换至下一部件
}
else if(k->key() == Key_W)
{
if(k->state() == Qt::ShiftButton)
{
this->resize(100,100);//当按下Shift+W时改变窗口大小
}
}
}
但是,有一些特殊的按键比如说Tab键,如果在keyPressEvent中实现则是不能成功的,因为默认Tab事件(切换焦点)被先捕获了,默认Tab和Shift+Tab事件定义在qwidget.h中,代码为:
case QEvent::KeyPress: {
QKeyEvent *k = (QKeyEvent *)e;
bool res = FALSE;
if ( k->key() == Key_Backtab ||
(k->key() == Key_Tab &&
(k->state() & ShiftButton)) ) {
QFocusEvent::setReason( QFocusEvent::Tab );
res = focusNextPrevChild( FALSE );
QFocusEvent::resetReason();
} else if ( k->key() == Key_Tab ) {
QFocusEvent::setReason( QFocusEvent::Tab );
res = focusNextPrevChild( TRUE );
QFocusEvent::resetReason();
}
}
所以我们要在之前就实现我们自己的Tab事件.实现代码如下:
bool MyWidget::event(QEvent *event)
{
if (event->type() == QEvent::KeyPress)
{
QKeyEvent *ke = static_cast(event);
if (ke->key() == Qt::Key_Tab)
{ // special tab handling here return true;
}
}
else if (event->type() == MyCustomEventType)
{
MyCustomEvent *myEvent = static_cast(event); // custom event handling here return true;
} return QWidget::event(event);
}