A downloaded Image over map

take a look on my code:

 AxMap1.Refresh()
    Dim minX As Double = 0
    Dim minY As Double = 0
    Dim maxX As Double = 0
    Dim maxY As Double = 0
    AxMap1.PixelToDegrees(0, AxMap1.Height, minX, minY)
    AxMap1.PixelToDegrees(AxMap1.Width, 0, maxX, maxY)
    Dim a1 As String = minX.ToString.Replace(",", ".")
    Dim a2 As String = minY.ToString.Replace(",", ".")
    Dim a3 As String = maxX.ToString.Replace(",", ".")
    Dim a4 As String = maxY.ToString.Replace(",", ".")
    Dim hh As String = AxMap1.Height.ToString
    Dim ww As String = AxMap1.Width.ToString
    Dim url As String
    url = "https://wms.cartografia.agenziaentrate.gov.it/inspire/wms/ows01.php?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&FORMAT=image%2Fpng&TRANSPARENT=true&LAYERS=" & ProvinceLAYER & FogliLAYER & ParticelleLAYER & AcqueLAYER & StradeLAYER & FabbricatiLAYER & CodiceLAYER & GraffaLAYER & "copyright&CRS=EPSG%3A6706&WIDTH=" & ww & "&HEIGHT=" & hh & "&BBOX=" & a2 & "," & a1 & "," & a4 & "," & a3
    Dim matricecolore As New Drawing.Imaging.ColorMatrix
    Dim attributi As New Drawing.Imaging.ImageAttributes
    Dim mywc As New WebClient
    Dim immagine As New Bitmap(System.Drawing.Image.FromStream(New MemoryStream(mywc.DownloadData(url))))
    matricecolore.Matrix33 = WMSopacity
    attributi.SetColorMatrix(matricecolore)
    AxMap1.CreateGraphics.DrawImage(immagine, New Rectangle(0, 0, immagine.Width, immagine.Height), 0, 0, immagine.Width, immagine.Height, GraphicsUnit.Pixel, attributi)

my goal is to see the image above the map but it disappears immediately
help me please! :smiley: