如何在Ubuntu QML应用中播放视频

在这篇文章中，我们将介绍如何在Ubuntu QML应用中播放一个视频。为了实现方便，我们可以事先用手机录下一个视频，并置于我们已经创建好的项目中。

首先，我们利用Ubuntu SDK来创建一个“QML app with Simple UI (qmake)”的项目。我们修改我们的Main.qml文件如下：

import QtQuick 2.0
import Ubuntu.Components 1.1
import QtMultimedia 5.0

/*!
    \brief MainView with a Label and Button elements.
*/

MainView {
    // objectName for functional testing purposes (autopilot-qt5)
    objectName: "mainView"

    // Note! applicationName needs to match the "name" field of the click manifest
    applicationName: "video.liu-xiao-guo"

    /*
     This property enables the application to change orientation
     when the device is rotated. The default is false.
    */
    //automaticOrientation: true

    // Removes the old toolbar and enables new features of the new header.
    useDeprecatedToolbar: false

    width: units.gu(60)
    height: units.gu(85)

    Page {
        title: i18n.tr("Video")

        Video {
            id: video
            anchors.fill: parent
            source: "sample.mp4"

            focus: true

            Keys.onSpacePressed: {
                video.playbackState == MediaPlayer.PlayingState ? video.pause() : video.play()
            }

            Keys.onLeftPressed: video.seek(video.position - 5000)
            Keys.onRightPressed: video.seek(video.position + 5000)
        }

        Button {
            anchors.bottom: parent.bottom
            anchors.horizontalCenter: parent.horizontalCenter
            anchors.bottomMargin: units.gu(1)
            text: "Play"

            onClicked: {
                video.play()
            }
        }

        Image {
            id:left
            width: units.gu(4)
            height: width
            anchors.left: parent.left
            anchors.bottom: parent.bottom
            anchors.leftMargin: units.gu(1)
            anchors.bottomMargin: units.gu(1)
            source: "icon-left-arrow.png"

            MouseArea {
                anchors.fill: parent
                onClicked: {
                    video.seek(video.position - 1000);
                }
            }
        }

        Image {
            id:right
            width: units.gu(4)
            height: width
            mirror: true
            anchors.right: parent.right
            anchors.bottom: parent.bottom
            anchors.rightMargin: units.gu(1)
            anchors.bottomMargin: units.gu(1)
            source: "icon-left-arrow.png"

            MouseArea {
                anchors.fill: parent
                onClicked: {
                    video.seek(video.position + 1000);
                }
            }
        }
    }
}

import QtMultimedia 5.0

我们需要同时修改我们的.pro文件来安装我们的sample.mp4视频文件到手机中：

TEMPLATE = aux
TARGET = video

RESOURCES += video.qrc

QML_FILES += $$files(*.qml,true)              $$files(*.js,true)              $$files(*.mp4,true)
             $$files(*,true)

CONF_FILES +=  video.apparmor                video.desktop                video.png

OTHER_FILES += $${CONF_FILES}                $${QML_FILES}

#specify where the qml/js files are installed to
qml_files.path = /video
qml_files.files += $${QML_FILES}

#specify where the config files are installed to
config_files.path = /video
config_files.files += $${CONF_FILES}

INSTALLS+=config_files qml_files

我们可以通过左下角和右下角的箭头按钮来快进或后退。按下中间的按钮“Play”可以用来播放视频。

项目的源码在：git clone https://gitcafe.com/ubuntu/video.git