I HATE WRITEABLEBITMAP

Hi guys,

I'm trying to create at runtime a simple 81x81 bitmap, and store it into a database using byte array...

This is the code i wrote

Public Sub CreateScreenShotRecord()
        Try
            Dim oMemoryStream As New System.IO.MemoryStream()
            Dim objWB As New WriteableBitmap(81, 81)
            Dim objTransform As New Windows.Media.TranslateTransform()
            Dim objStreamSource As StreamResourceInfo

            objStreamSource = Application.GetResourceStream(New Uri("Images\shot.jpg", UriKind.Relative))
            objWB.LoadJpeg(objStreamSource.Stream)
            objWB.Invalidate()

            objTransform.X = 10
            objTransform.Y = 10
            objWB.Render(_objBlue, objTransform)
            objWB.Invalidate()

            objTransform = New Windows.Media.TranslateTransform()
            objTransform.X = 20
            objTransform.Y = 20
            objWB.Render(_objFucsia, objTransform)

            objTransform = New Windows.Media.TranslateTransform()
            objTransform.X = 30
            objTransform.Y = 30
            objWB.Render(_objGreen, objTransform)
            objWB.Invalidate()

            objWB.SaveJpeg(oMemoryStream, objWB.PixelWidth, objWB.PixelHeight, 0, 100)
            oMemoryStream.Seek(0, IO.SeekOrigin.Begin)

            __y_ImageByteArray = oMemoryStream.GetBuffer
        Catch ex As Exception
            __y_ImageByteArray = Nothing
        End Try
    End Sub

_objBlue, _objGreen, _objFucsia are public images variables and __y_ImageByteArray is a public byte array

So the problem is...:::

when i call this sub, the first time i execute the sub, the result image (stored into the __y_ImageByteArray variable) is equal of the base image ...Uri("Images\shot.jpg"...without any other images rendered, but the second time i execute the sub the result image is correct...

I can't understand the problem, i think SaveJpeg is async operation, but i'm not able to understand if the SaveJpeg has finished to write the memory stream or not...

Sorry for my bad english!

Daniele

TNX in advance