qt按键焦点切换
实现内容
对于4个控件，当按下左右按键时焦点可以左右切换，如下图：
关键代码
1.实现焦点切换功能
使用事件过滤器来对事件进行分类处理这样就可以在a1至a4等控件上实现，按下右键后即把焦点转到右边控件上的功能。
先在aa.h中加入
public slots:
booleventFilter(QObject *,QEvent *);
在aa.cpp中定义函数
bool aa::eventFilter(QObject *watched, QEvent*event)
{
if(watched == ui->a1 || watched == ui->a2 || watched == ui->a3|| watched == ui->a4)//确认可控的控件
{
if(event->type() == QEvent::KeyPress)//如果检测到按键
{
bool f1 =ui->a1->hasFocus();
bool f2 =ui->a2->hasFocus();
bool f3 =ui->a3->hasFocus();
bool f4 =ui->a4->hasFocus();定义4个获得焦点的状态
QKeyEvent *key_event = static_cast
if(key_event->key() == Qt::Key_Right)//右键
{
if(f1)//焦点在a1处
{
focusNextChild();//焦点移动
ui->a2->setFocus();//移动到a2
}
if(f2)
{
focusNextChild();
ui->a3->setFocus();
}
if(f3)
{
focusNextChild();
ui->a4->setFocus();
}
}
if(key_event->key() == Qt::Key_Left)
{
if(f4)
{
focusNextChild();
ui->a3->setFocus();
}
if(f3)
{
focusNextChild();
ui->a2->setFocus();
}
if(f2)
{
focusNextChild();
ui->a1->setFocus();
}
}
}
}
return QWidget::eventFilter(watched,event); //最后将事件交给上层对话框
}
左键功能定义稍加修改即可
2.实现动态焦点背景色变化功能
if (watched==ui->a1) //
{
if (event->type()==QEvent::FocusIn) //然后再判断控件的具体事件(这里指获得焦点事件)
{
QPalette p=QPalette();
p.setColor(QPalette::Button,Qt::yellow);
ui->a1->setPalette(p);
}
另一种实现方法
另外一般的焦点切换还可以使用setCurrentItem函数实现，下面是在网上看到的代码：
bool MainForm::eventFilter(QObject *obj,QEvent *event)
{
if(obj==ComboBox_Keyboard){
if(event->type()== QEvent::KeyPress)
{
QKeyEvent*keyEvent = static_cast
if(keyEvent->key()== 4100)//ENTER
on_ComboBox_Keyboard(ComboBox_Keyboard->currentItem());
if(keyEvent->key()== 4117){//DOWN
if(ComboBox_Keyboard->currentItem()==ComboBox_Keyboard->count()-1)
ComboBox_Keyboard->setCurrentItem(0);
else
ComboBox_Keyboard->setCurrentItem(ComboBox_Keyboard->currentItem()+1);}
if(keyEvent->key()== 4115){//UP
if(ComboBox_Keyboard->currentItem()==0)
ComboBox_Keyboard->setCurrentItem(ComboBox_Keyboard->count()-1);
else
ComboBox_Keyboard->setCurrentItem(ComboBox_Keyboard->currentItem()-1);}
returnTRUE;
}else{
returnFALSE;
}
}
…………
}
参考资料:
http://zoreraul.blog.163.com/blog/static/725739282010828104621410/
http://zhidao.baidu.com/link?url=4DCT55CnwXzT1nC28f0oPb36rrlK7bp0eohV61gtlZY0IvzLucMRqMvIjNHq4Oc5_horjUhyDkeSy0A1VYW7hK