如何将 QKeyEvent 发送到特定的 qml 项目?

How to send QKeyEvent to specific qml item?

我正在尝试将自定义 QKeyEvent(如 Keypress 键 B)发送到我的 [=35] 中的项目(如 TextField) =]QML 文件。这是我写的,它不起作用。似乎项目 (TextField) 没有得到我的事件(我假设这是因为没有 B 字符附加到我的 TextField 的文本)。我在 ClickHandler class 中捕获 click signal 然后在 handleClick slot,我尝试 post 自定义 event 到我的 focused item,这里是 TextField.

ClickHandler.h

class ClickHandler : public QObject
{
    Q_OBJECT
    QQmlApplicationEngine* engine;
    QApplication* app;
public:
    explicit ClickHandler(QQmlApplicationEngine *,QApplication* app);

signals:

public slots:
    void handleClick();
};

ClickHandler.cpp:

#include "clickhandler.h"
#include <QMessageBox>
#include <QQuickItem>

ClickHandler::ClickHandler(QQmlApplicationEngine* engine, QApplication* app)
{
    this->engine = engine;
    this->app = app;

}

void ClickHandler::handleClick()
{
    QObject* root = engine->rootObjects()[0];
    QQuickItem *item = (root->property("activeFocusItem")).value<QQuickItem *>();
    if (item == NULL)
        qDebug() << "NO item";
    QKeyEvent* event = new QKeyEvent(QKeyEvent::KeyPress,Qt::Key_B,Qt::NoModifier);
    QCoreApplication::postEvent(item,event);
}

main.cpp:

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

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    QObject* root = engine.rootObjects()[0];
    ClickHandler* ch = new ClickHandler(&engine, &app);
    QQuickItem* button = root->findChild<QQuickItem*>("button");

    QObject::connect(button, SIGNAL(clicked()), ch, SLOT(handleClick()));

    return app.exec();
}

main.qml:

ApplicationWindow {
    objectName: "rootWindow"
    visible: true
    Column {
        TextField {
            id: textId1
            objectName: "text1"
            text: "text1 message"
            focus: true
        }

        TextField {
            id: textId2
            objectName: "text2"
            text: "text2 message"
        }
        Button {
            objectName: "button"
            text : "Click me";
        }
    }
}

如果您实施 onPressed 处理程序,您可以看到问题出在哪里。

ApplicationWindow {
    objectName: "rootWindow"
    visible: true
    Column {
        TextField {
            id: textId1
            objectName: "text1"
            text: "text1 message"
            focus: true

            Keys.onPressed: {
                console.log("textId1: " + event.key + " : " + event.text)
            }
        }

        TextField {
            id: textId2
            objectName: "text2"
            text: "text2 message"

            Keys.onPressed: {
                if (event.key === Qt.Key_B) {
                    console.log("I like B's but not QString's")
                }
            }
        }

...

此代码打印 qml: textId1: 66 : 因为该键的文本为空。

您需要使用如下方式创建活动:

Qt::Key key = Qt::Key_B;
QKeyEvent* event = new QKeyEvent(QKeyEvent::KeyPress,
                                 key,
                                 Qt::NoModifier,
                                 QKeySequence(key).toString());