RowLayout is not a type

[white]

This issue is similar with the one that I have asked before, but in fact, it is not completely same.
I have made one simple code using QML (5.14.2), when I compile the code ,it give error : "qrc:/main.qml:28:17: RowLayout is not a type"

I really not know what the really reason for this one because I have already import the "QtQuick.Controls 1.4" .

I guess it may case the mix using control 1 and control 2 together. Hope to get get some help for :

1. how to fix this issue and what is the reason for this error ?
2. is there some of specification or conduct for using version of qml control ? (something like that)

The code I am using is :

import QtQuick 2.12

import QtQuick.Controls 1.4

ApplicationWindow {
visible: true
width: 640
height: 480
title: qsTr("Scroll")

Item {
    id: inforWindow
    anchors.fill: parent

    TableView {
        id: inforWindowView
        anchors.fill: parent.anchors.fill

        Tab {
            id: inforWindowViewTab

            title : "123-case"

            Text {
                id: inforWindowViewTabText
                text: qsTr("text")
            }

            RowLayout {   //here is the error reported.
                spacing: 6
                anchors.fill: parent
                Button {
                    id: caseInforEnterBtn
                    anchors.bottom: parent.bottom
                    anchors.right: parent.right

                    width: 50

                    text: qsTr("Enter")
                }

                ComboBox {
                    anchors.left: parent.left
                    anchors.right: caseInforEnterBtn.left
                    anchors.verticalCenter: caseInforEnterBtn.verticalCenter
                }

            }
        }
        Tab {
            title: qsTr("general")
        }
    }
}

}

[eyllanesc]

@white The documentation is very clear:

[white]

Thanks for your .
Yes, I miss it.

[RokeJulianLockhart]

This post is deleted!