qt 实现的电视遥控系统，如何让qt响应来自遥控器的按键信息？

Posted 2021-01-28 senior-engineer

 

结帖率 60%

如题：
目前在做一个项目，使用qt实现一个类似于机顶盒的遥控系统，那么关键的问题来了,如何让qt响应遥控器的按键信息呢？

应该分两步吧：
1.搭载qt的终端接收来自遥控器的按键信息，并解析，通信方式可以是蓝牙或者红外
2.qt获取解析后的按键信息，并响应

第一步已经实现了，关键我对qt了解实在不深，第二步想着应该类似于qt响应键盘吧，
键盘：通信方式是usb接口线，通过键盘驱动获取按键信息后，qt识别并响应此事件，UI上做响应操作如：焦点移动、输入字符等
遥控器：通信方式蓝牙或红外，自己写了个驱动，获取到按键信息解析后，qt？？？？

是的，遥控器关键是qt没有相应的驱动，因而得自己做，我的想法是或许可以做一个类似的虚拟键盘？

求大神指导.....
是自定义一个事件做一个虚拟键盘呢 还是有其他更好的方案呢？

 

QKeyEvent upKey(QEvent::KeyPress, Qt::Key_Up, Qt::NoModifier);
QCoreApplication::sendEvent(your_widget, &leftKey);

这个应该可以，不过我的UI是用qml做的，将事件发送到当前界面还是一个问题...

 

我的解决方案：
创建一个c++类：模拟键盘按键类，功能发送键盘事件到指定的UI对象
模拟按键类如下：
CKeyEvent.h

class CKeyEvent : public QObject
{
    Q_OBJECT

    Q_ENUMS(CKEY_ID)

public:
    enum CKEY_ID
    {
        CKEY_UP = Qt::Key_Up,
        CKEY_DOWN= Qt::Key_Down,
        CKEY_MAX
    };
    CKeyEvent(QObject *parent = NULL);
    ~CKeyEvent();

    Q_INVOKABLE void sendCkeyPressEvent(QObject* receiver,Qt::Key CkeyId);
    Q_INVOKABLE void sendCkeyReleaseEvent(QObject* receiver,Qt::Key CkeyId);

private:
    QObject* m_receiver;
};

类的实现：
CKeyEvent.cpp

CKeyEvent::CKeyEvent(QObject *parent):QObject(parent)
{

}
CKeyEvent::~CKeyEvent()
{

}

void CKeyEvent::sendCkeyPressEvent(QObject* receiver,Qt::Key CkeyId)
{
    QKeyEvent keyPressEvent(QEvent::KeyPress, CkeyId, Qt::NoModifier);
    QGuiApplication::sendEvent(receiver, &keyPressEvent);
}
void CKeyEvent::sendCkeyReleaseEvent(QObject* receiver,Qt::Key CkeyId)
{
    QKeyEvent keyReleaseEvent(QEvent::KeyRelease, CkeyId, Qt::NoModifier);
    QGuiApplication::sendEvent(receiver, &keyReleaseEvent);
}

主函数：main.cpp

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);


    //注册C++类到QML
    //qmlRegisterType<CKeyEvent>("CKeyEvent", 1, 0, "CKeyEvent");

    QQmlApplicationEngine engine;

    CKeyEvent *Ckey = new CKeyEvent();
    engine.rootContext()->setContextProperty("cKeyCDP",Ckey);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    return app.exec();
}

　　QML：main.qml

Window {
    id : mainWindows
    visible: true
    width: 1024
    height: 768
    title: qsTr("Hello World")

    GridMenu {
        id: gridMenu
        y: 320; width: parent.width; height: 320
        activeFocusOnTab: true
    }

    Button
    {
        id :keyUp
        anchors.top:keyFocus.top
        anchors.topMargin: 20
        anchors.left : keyFocus.right
        anchors.leftMargin: 20
        width: 100
        height: 60

        text: qsTr("up")

        onClicked:
        {
            cKeyCDP.sendCkeyPressEvent(mainWindows,Qt.Key_Up);
            cKeyCDP.sendCkeyReleaseEvent(mainWindows,Qt.Key_Up);
        }

    }
    Button
    {
        id :keyDown
        anchors.top:keyUp.bottom
        anchors.topMargin: 20
        anchors.left : keyFocus.right
        anchors.leftMargin: 20
        width: 100
        height: 60

        text: qsTr("down")
        onClicked:
        {
            cKeyCDP.sendCkeyPressEvent(mainWindows,Qt.Key_Down);
            cKeyCDP.sendCkeyReleaseEvent(mainWindows,Qt.Key_Down);
        }
    }
}

　　GridMenu.qml:

FocusScope {
    property alias interactive: gridView.interactive

    onActiveFocusChanged: {
        //if (activeFocus)
            //mainView.state = "showGridViews"
    }

    Rectangle {
        anchors.fill: parent
        clip: true
        gradient: Gradient {
            GradientStop { position: 0.0; color: "#193441" }
            GradientStop { position: 1.0; color: Qt.darker("#193441") }
        }

        GridView {
            id: gridView
            anchors.fill: parent; anchors.leftMargin: 20; anchors.rightMargin: 20
            cellWidth: 152; cellHeight: 152
            focus: true
            model: 12

            //KeyNavigation.up: tabMenu
            //KeyNavigation.down: listMenu
            //KeyNavigation.left: contextMenu

            delegate: Item {
                id: container
                width: GridView.view.cellWidth; height: GridView.view.cellHeight

                Rectangle {
                    id: content
                    color: "transparent"
                    antialiasing: true
                    anchors.fill: parent; anchors.margins: 20; radius: 10

                    Rectangle { color: "#91AA9D"; anchors.fill: parent; anchors.margins: 3; radius: 8; antialiasing: true }
                    Image { source: "images/qt-logo.png"; anchors.centerIn: parent }
                }

                MouseArea {
                    id: mouseArea
                    anchors.fill: parent
                    hoverEnabled: true

                    onClicked: {
                        container.GridView.view.currentIndex = index
                        container.forceActiveFocus()
                    }
                }

                states: State {
                    name: "active"; when: container.activeFocus
                    PropertyChanges { target: content; color: "#FCFFF5"; scale: 1.1 }
                }

                transitions: Transition {
                    NumberAnimation { properties: "scale"; duration: 100 }
                }
            }
        }
    }
}

通过点击UI上的两个按钮：‘UP’   ‘DOWN‘

可以实现键盘‘up’ ‘down‘的功能：使焦点上下移动

安卓Tv开发（二）移动智能电视之焦点控制（按键事件）Instrumentation提供了丰富的以send开头的函数接口来实现模拟键盘和鼠标。本系列将实现遥控器焦点控制，模