How can I use Material and Universal Design?

[Ibrahim]

Hi; I wrote this code:

import QtQuick 2.6
import QtQuick.Window 2.2
import Qt.labs.controls 1.0
import Qt.labs.controls.material 1.0

ApplicationWindow {
  visible: true
  width: 720
  height: 520

  Material.accent: Material.Blue
  Material.theme: Material.Dark

  MainForm {
    anchors.fill: parent

  }
}

But my application is not material design on the Android 4.4.4 device. How can I do it? Thanks.