Hi Guys,

I'm in the process of writing a .NET app that shows a preview image of the drawing sheets for a selected file. I am using the code below which I got from here: 2017 SOLIDWORKS API Help - Get Preview Bitmaps of Drawing Sheets Example (VB.NET) and here: 2017 SOLIDWORKS API Help - Get PNG Preview Bitmap and Stream for Configuration Example (VB.NET). The issue I am having I will get blank sheets previews for some sheets but not others. Any help or advice is appreciated.

<p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">    Public Function SheetImages(SelectionName As String) As Image<br>        Dim swClassFact As SwDMClassFactory<br>        Dim swDocMgr As ISwDMApplication<br>        Dim swDoc As SwDMDocument10<br>        Dim sDocFileName As String = BrowseTB.Text<br>        Dim nDocType As SwDmDocumentType<br>        Dim nRetVal As SwDmDocumentOpenError<br>        Dim sLicenseKey As String = My.Settings.swDocMgrKey<br>        Dim swCfgMgr As SwDMConfigurationMgr<br>        Dim vCfgNameArr As Object<br>        Dim vCfgName As Object<br>        Dim swCfg As SwDMConfiguration7</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">        swClassFact = CreateObject("SwDocumentMgr.SwDMClassFactory")<br>        swDocMgr = swClassFact.GetApplication(sLicenseKey)</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">        If InStr(LCase(sDocFileName), "sldprt") > 0 Then<br>            nDocType = SwDmDocumentType.swDmDocumentPart<br>        ElseIf InStr(LCase(sDocFileName), "sldasm") > 0 Then<br>            nDocType = SwDmDocumentType.swDmDocumentAssembly<br>        ElseIf InStr(LCase(sDocFileName), "slddrw") > 0 Then<br>            nDocType = SwDmDocumentType.swDmDocumentDrawing<br>        Else<br>            nDocType = SwDmDocumentType.swDmDocumentUnknown<br>            Return Nothing<br>            Exit Function<br>        End If</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">        If nDocType = SwDmDocumentType.swDmDocumentDrawing Then<br>            swDoc = swDocMgr.GetDocument(sDocFileName, nDocType, True, nRetVal)<br>            If (swDoc Is Nothing) Then<br>                MsgBox("Unable to open document.")<br>            End If<br>            Dim Sheets As Object<br>            Dim Sheet As SwDMSheet2<br>            Dim nError As Integer<br>            Sheets = swDoc.GetSheets<br>            Dim nbrSheets As Integer<br>            nbrSheets = CLng(UBound(Sheets)) + 1<br>            Dim snbrSheets As String = Convert.ToString(nbrSheets)<br>            Dim i As Integer<br>            For i = 0 To UBound(Sheets)<br>                Sheet = Sheets(i)<br>                If Sheet.Name = SelectionName Then<br>                    Dim objBitMap As Object = Sheet.GetPreviewPNGBitmap(nError)<br>                    If nError = 0 Then<br>                        Dim imgPreview As System.Drawing.Image = PictureDispConverter.Convert(objBitMap)<br>                        Return imgPreview<br>                        imgPreview.Dispose()<br>                        Exit Function<br>                    Else<br>                        Select Case nError<br>                            Case 2<br>                                MsgBox("Error: No preview data stored with document.")<br>                            Case 4<br>                                MsgBox("Error: Failed to make the bitmap.")<br>                        End Select<br>                    End If<br>                End If<br>            Next<br>            swDoc.CloseDoc()<br>        ElseIf nDocType = SwDmDocumentType.swDmDocumentAssembly Or nDocType = SwDmDocumentType.swDmDocumentPart Then<br>            swDoc = swDocMgr.GetDocument(sDocFileName, nDocType, True, nRetVal)<br>            swCfgMgr = swDoc.ConfigurationManager<br>            vCfgNameArr = swCfgMgr.GetConfigurationNames<br>            For Each vCfgName In vCfgNameArr<br>                If vCfgName = SelectionName Then<br>                    swCfg = swCfgMgr.GetConfigurationByName(vCfgName)<br>                    Dim objBitMap As Object = swCfg.GetPreviewBitmap(nRetVal)<br>                    Dim imgPreview As System.Drawing.Image = PictureDispConverter.Convert(objBitMap)<br>                    Return imgPreview<br>                    imgPreview.Dispose()<br>                    Exit Function<br>                End If<br>            Next<br>            swDoc.CloseDoc()<br>        Else<br>            Return Nothing<br>            Exit Function<br>        End If</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">        Return Nothing<br>    End Function</span></p>

<p></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">Public Class PictureDispConverter</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">    Inherits AxHost</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">    Public Sub New()<br>        MyBase.New("56174C86-1546-4778-8EE6-B6AC606875E7")<br>    End Sub</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">    Public Shared Function Convert(ByVal objIDispImage As Object) As System.Drawing.Image<br>        Dim objPicture As Image<br>        objPicture = GetPictureFromIPicture(objIDispImage)<br>        Return objPicture<br>    End Function</span></p><p><span style="color: #0000ff; font-family: Consolas; font-size: 10pt;">End Class</span></p><p></p>