在Qt C ++中使用多个键 [英] Using multiple keys in Qt C++

问题描述

我正在构建坦克"游戏，在该游戏中，我使用Key事件在地图上运行我的坦克.实际上，我一次只能使用一个键，但是我需要具备f.e.同时向上和向左走.

I'm building the "Tanks" game where I'm using Key event to run my tank on map. Actually I can only use one key at the time but I need to have ability to f.e. go up and left simultaneously.

这是我的单键事件代码:

Here's my code for single key events:

switch(event->key())
{
case Qt::Key_Up:
    if(!ui->widget->playerList[playerID]->canMove(0.3, 20, 20, -20, -20, 1.5)) return;
    ui->widget->playerList[playerID]->move(0.3);
    ui->widget->updateGL();
    break;
case Qt::Key_Down:
    if(!ui->widget->playerList[playerID]->canMove(-0.2, 20, 20, -20, -20, 1.5)) return;
    ui->widget->playerList[playerID]->move(-0.2);
    ui->widget->updateGL();
    break;
case Qt::Key_Right:
    ui->widget->playerList[playerID]->rotate(10);
    ui->widget->updateGL();
    break;
case Qt::Key_Left:
    ui->widget->playerList[playerID]->rotate(-10);
    ui->widget->updateGL();
    break;
case Qt::Key_Q:
    ui->widget->playerList[playerID]->rotateCannon(10);
    ui->widget->updateGL();
    break;
case Qt::Key_E:
    ui->widget->playerList[playerID]->rotateCannon(-10);
    ui->widget->updateGL();
    break;
default:
    QMainWindow::keyPressEvent(event);
    break;
} 

推荐答案

您可以将按键添加到按键组中，并在释放按键时从该按键组中删除.因此，您可以将按下的键添加到作为类成员的QSet中:

You can add a pressed key to the set of pressed keys and remove from this set when the key is released. So you can add the pressed key to a QSet which is a class member :

QSet<int> pressedKeys;

您可以在事件过滤器中捕获关键事件:

You can catch the key events in an event filter :

bool MyWidget::eventFilter(QObject * obj, QEvent * event)
{

    if(event->type()==QEvent::KeyPress) {

        pressedKeys += ((QKeyEvent*)event)->key();

        f( pressedKeys.contains(Qt::Key_Up) && pressedKeys.contains(Qt::Key_Left) )
        {
            // up and left is pressed
        }

    }
    else if(event->type()==QEvent::KeyRelease)
    {

        pressedKeys -= ((QKeyEvent*)event)->key();
    }


    return false;
}

不要忘记在构造函数中安装事件过滤器:

Don't forget to install the event filter in the constructor:

this->installEventFilter(this);

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