Qt SCXML 媒体播放器 QML 范例 (静态)

A Qt Quick application that sends data to and receives it from a compiled ECMAScript data model.

Media Player QML Example (Static) demonstrates how to access data from an ECMAScript data model that is compiled into a C++ class.

UI 是使用 Qt Quick 创建的。

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 .

使用 ECMAScript 数据模型

We specify the data model as a value of the datamodel 属性在 <scxml> element in mediaplayer-common/mediaplayer.scxml :

<scxml
    xmlns="http://www.w3.org/2005/07/scxml"
    version="1.0"
    name="MediaPlayerStateMachine"
    initial="stopped"
    datamodel="ecmascript"
>
    <datamodel>
        <data id="media"/>
    </datamodel>

编译状态机

We link against the Qt SCXML module by adding the following line to the .pro 文件：

QT += widgets scxml

接着，指定要编译的状态机：

STATECHARTS = ../mediaplayer-common/mediaplayer.scxml

Qt SCXML 编译器 qscxmlc , is run automatically to generate statemachine.h and statemachine.cpp , and to add them to the HEADERS and SOURCES variables for compilation.

实例化状态机

We instantiate the generated MediaPlayerStateMachine class in mediaplayer-qml-static.cpp :

#include "mediaplayer.h"
int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    qmlRegisterType<MediaPlayerStateMachine>("MediaPlayerStateMachine", 1, 0, "MediaPlayerStateMachine");
    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:///mediaplayer-qml-static.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;
    return app.exec();
}

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