ApplicationWindow不遵守大小

Question

I'm having an issue understanding the width and the height attributes of the ApplicationWindow setting in a very simple IOS program. Take for instance the following code:

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.2
import QtQuick.Layouts 1.1

ApplicationWindow {
    title: "Hellow"
    width: 1024
    height: 1920
    visible: true

    Rectangle{
        width: 300
        height: 300
        color: "blue"
    }
}

When I compile using Qt 5.5 my blue Rectangle appears much larger than I would expect. I've played with the width and height of the Rectangle and it seems like the ApplicationWindow is more on the order of width: 390 , height: 650 regardless of what I have set.

Any thoughts? Thanks

Answer 1

The High DPI Displays documentation might be useful here. In particular, you could try setting QT_DEVICE_PIXEL_RATIO to 1 before running your application and see if that results in the Rectangle being sized in the way you want it to be.

Answer 2

This link answers my question.

https://forum.qt.io/topic/43513/solved-ios-retina/6

Specifically from there:

On iOS the dimension that you get is the logical dimension of the iOS screens. This happens also if you program natively with Xcode on iOS. So, when you create a Rectangle of 320 logical pixel, on non-Retina iOS devices it will use 302 real pixel, but on retina iOS devices it will use the double of pixel (640).

The link also offers some additional advice on how to get screen independent drawing.