QML 软木板范例

A QML example about displaying NFC Data Exchange Format (NDEF) messages.

The QML corkboard example displays the contents of NDEF messages read from an NFC Tag. Each newly detected NDEF message is added to the corkboard and can be dragged into an arbitrary position on the board. The corkboard has a Personal and Work space. The workspace can be changed by sliding left or right.

实现细节

In the corkboard example, we use the following .qml files:

corkboards.qml
Mode.qml

The main.cpp holds the application logic to load the main view stored in the corkboards.qml file.

int main(int argc, char *argv[])
{
    QGuiApplication application(argc, argv);
    QQuickView view;
    view.setSource(QUrl("qrc:/corkboards.qml"));
    view.setResizeMode(QQuickView::SizeRootObjectToView);
    view.show();
    return application.exec();
}

corkboards.qml 细节

There are two basic QML components in this file:

NearField
ListView

The first time the NearField QML type is instantiated, the Component.onCompleted handler will start the NFC polling process. The onMessageRecordsChanged handler parses NFC Messages that are detected by the NearField component and builds up a data model that is passed into the ListView. Additionally, every time the NearField manager stops the polling process, the onPollingChanged handler restarts it.

    NearField {
        property bool requiresManualPolling: false
        orderMatch: false
        onMessageRecordsChanged: {
        ...
        onPollingChanged: {
        ...
        Component.onCompleted: {
        ...
        }

The ListView component takes a ListModel as parameter (built from the NFC records). The view of each of the items of the model is defined by the Mode component (its implementation details can be found in the file Mode.qml). The data model consists of a list of corkboards. Each corkboard can display multiple NFC text message records.

    ListView {
        id: listView
        ...
        model: list
        ...
        delegate: Mode {}
    }

Mode.qml 细节

A corkboard title is displayed for each of the items that form part of the data model:

        Text {
            anchors { horizontalCenter: parent.horizontalCenter; top: parent.top; topMargin: 10}
            text: name;
            font { pixelSize: 30; bold: true }

Every text record that was read from an NFC message, is represented by a sticky note with its own position on the display. Initially the position is set randomly. The text on the sticky note is set on a TextField.

        Repeater {
            model: notes
            Item {
                id: stickyPage
                x: ListView.width * (0.7 * Math.random() + 0.1)
                y: ListView.height * (0.7 * Math.random() + 0.1)
                ...
                Item {
                    id: sticky
                    ...
                    TextEdit {
                        id: myText
                        text: noteText
                        ...
                    }
                    ...

运行范例

要运行范例从 Qt Creator ，打开欢迎模式，然后选择范例从范例。更多信息，拜访构建和运行范例 .

范例工程 @ code.qt.io

另请参阅 Qt NFC .