qt - QML 在应用程序启动时筛选不正确的属性

Question

我在开始时需要正确的屏幕尺寸，但如果我执行以下代码:

import QtQuick 2.0
import QtQuick.Window 2.0

Rectangle {

    MouseArea {
        anchors.fill: parent
        onClicked: {
            console.log( Screen.height, Screen.width, Screen.desktopAvailableHeight, Screen.desktopAvailableWidth);
        }
    }

    Component.onCompleted: {
        console.log( Screen.height, Screen.width, Screen.desktopAvailableHeight, Screen.desktopAvailableWidth);
    }
}

我一开始有零
并在鼠标单击时校正屏幕尺寸

0 0 0 0
1200 1920 1133 1920

怎么能看出这是什么？
以及如何在应用程序开始时获得正确的屏幕尺寸？

Answer 1

目前我正在解决类似的问题。
来自 Screen documentation :

Note that the Screen type is not valid at Component.onCompleted, because the Item or Window has not been displayed on a screen by this time

所以你将无法使用 onCompleted()从屏幕项目中获取屏幕尺寸。
但是，您可以从应用程序的 C++ 端获取此信息并传递给 QML 上下文:

QScreen* screen = QGuiApplication::primaryScreen();
QSize screenSize = screen->size();
QtQuick2ApplicationViewer viewer;
QQmlContext* qmlContext = viewer.rootContext();
qmlContext->setContextProperty("screenSize", screenSize);