qml ChartView改变窗口大小不卡顿的方法

当ChartView的绘图量很大时，改变其窗口大小时，意味着会频繁刷新绘制，可能会卡顿，下面是解决方案：

import QtQuick 2.15
import QtQuick.Controls 2.15
import QtCharts 2.15

ChartView {
    id: root
    antialiasing: false
    legend.visible: false
    margins.left: 0
    margins.right: 0
    margins.bottom: 0
    margins.top: 0
    backgroundColor: "#00000000"
    plotAreaColor: "#00000000"
    // backgroundColor: "#9000ff00"
    // plotAreaColor: "#80ff0000"
    backgroundRoundness: 0
    dropShadowEnabled: false
    //theme: ChartView.ChartThemeHighContrast


    property bool windowResizing: false
    property var timer: null

    signal sigUpdatePlotAreaRect()

    onWidthChanged: handleWindowSizeChanged()
    onHeightCha