Qt Virtual Keyboard only shows a black rectangle when lauching InputPanel

0
votes

I am using Qt 5.12 and QtQuick.VirtualKeyboard 2.3 to develop an application on an embedded device. The problem is:

When I click the input field to enter something, only the inputpanel pops up, but there are no keys on the inputpanel. So the screen only shows a black rectangle for the virtual keyboard(As shown in the picture). I am pretty sure the black rectangle is the inputpanel. Because if I change the size of InputPanel in my code, the size of this black rectangle will also change.

I am wondering if anyone has met this problem before. What are the possible reasons for this issue? Are there any methods to display keys on inputPanel? Thanks!

This is image for the black rectangle shown on screen

This is the code for InputPanel:

InputPanel {
        id: inputPanel
        z: 99
        x: 0
        y: root.height
        width: root.width*2.1

        states: State {
            name: "visible"
            when: inputPanel.active
            PropertyChanges {
                target: inputPanel
                y: root.height - inputPanel.height
            }
        }
        transitions: Transition {
            from: ""
            to: "visible"
            reversible: true
            ParallelAnimation {
                NumberAnimation {
                    properties: "y"
                    duration: 250
                    easing.type: Easing.InOutQuad
                }
            }
        }
    }
}

This is the first line of my main.cpp file:

qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));

And this is the configurations in .pro file:

static {
    QT += svg
    QTPLUGIN += qtvirtualkeyboardplugin
}

CONFIG += disable-desktop
qtqmlvirtual-keyboardqtvirtualkeyboard