iOS Question Width of a Drawer

Private Sub Page1_Resize(Width As Int, Height As Int)
    Drawer.Resize(Width, Height)
End Sub

Private Sub Application_Start
    Page1.Initialize("Page1")
    Page1.RootPanel.LoadLayout("viewStartlogo") 'first time load a layout
    NavControl.ShowPage(Page1)
    Sleep(500)
    ShowDrawer
End Sub

Private Sub ShowDrawer
    Drawer.Initialize(Me, "Drawer", Page1.RootPanel, GetIdealDrawerWidth) 'only possible, if allready size known
    Drawer.CenterPanel.LoadLayout("viewMain")
    Drawer.LeftPanel.LoadLayout("viewMainLeft")
    Dim bb As BarButton
    bb.InitializeBitmap(LoadBitmapResize(File.DirAssets, "hamburger.png", 32dip, 32dip, True), "Drawer")
    Page1.TopLeftButtons = Array(bb)
End Sub

Sub GetIdealDrawerWidth() As Int
    Dim iWidth As Int = Min(Page1.RootPanel.Width, Page1.RootPanel.Height) ' Min(100%x, 100%y) 'if in Landscape mode
    iWidth = iWidth - 40dip ' https://blog.sebastiano.dev/material-navigation-drawer-sizing/
    Dim iMaxWidth As Int = 320dip : If iWidth > 500dip Then iMaxWidth = 400dip 'but max 320dp or 400dp with tablets
    iWidth = Min(iWidth, iMaxWidth)
    If iWidth <= 0 Then iWidth = 300dip 'if something went wrong
    Return iWidth
End Sub

    NavControl = Nav
    Page1.Initialize("Page1")
    '  Page1.RootPanel.LoadLayout("Page1") 
    NavControl.ShowPage (Page1)
    Wait For Page1_Resize (Width As Int, Height As Int)