ApplicationWindow "opacity" is error?

Alex_wang

import QtQuick.Controls 2.0
ApplicationWindow
{
opacity ： 0.8
}
error：
applicationwindow.opacity is not available due to component version

Eddy

Hi Alex_wang,

I don't know what version of Qt you are using. In Qt5.9 you can use :

import QtQuick 2.7

If I omit hits import directive I can reproduce your problem.

Eddy

Alex_wang

Qt version : 5.8.0
import QtQuick 2.5

Eddy

Can you check the highest import versions available on your system. AFAIR it could be for Qt5.8:

import QtQuick 2.7
import QtQuick.Controls 2.1

Eddy

Hi,

My attention was needed in the real world. Now I'm back, but unfortunately I cannot reproduce the use case where I didn't have any problems.

I found some similar bugs reports with the same error message but yours looks differently.

You could file a bug report for your case, unless somebody else knows a solution here.

Devopia53

@Alex_wang @Eddy

Hi.

It's not a bug.
It's releated to meta object revison.
Property oapacity of ApplicationWindow is defined as revison 1.
But, QtQuick.Controls 2 can only use revision 0.
Take a look at the defined type information for that plugin(aka. plugins.qmltypes) and following doc: http://doc.qt.io/qt-5/qtqml-cppintegration-definetypes.html#type-revisions-and-versions

jpnurmi

Hi, it is a bug and has been fixed in Qt 5.9.1.

jpnurmi

As a workaround, you could try setting the opacity in Component.onCompleted or using Binding element.

Eddy

@jpnurmi
Thanks for the feedback.

@Alex_wang : you can use it like this:

import QtQuick 2.7
import QtQuick.Controls 2.1
import QtQuick.Layouts 1.3


ApplicationWindow {
    id: app
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

 color: "yellow"

 Binding { target: app; property: "opacity"; value: 0.5}

Alex_wang

thanks all replies!
Thanks for Eddy and jpnurmi !