Marshalling error - getting DEVMODE from JOB_INFO_2

Right - the VB.Net spooler watch component is about 70% done but I am totally stuck on getting the DEVMODE structure as held in the pointer in JOB_INFO_2.

I keep getting the error:

Quote:

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An unhandled exception of type 'System.TypeLoadException' occurred in mscorlib.dll

Additional information:
Can not marshal field DeviceMode of type PrinterQueueWatch.JOB_INFO_2:
The type definition of this field has no layout information.

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I have the DEVMODE structure defined as a class thus:

Code:

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<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> _
Friend Class DEVMODE
    <VBFixedString(32), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=32)> Public pDeviceName As String  'CCHDEVICENAME
    Public dmSpecversion As Int16
    Public dmSize As Int16
    Public dmDriverExtra As Int16
    Public dmFields As Int32
    <MarshalAs(UnmanagedType.U2)> Public dmOrientation As PrintJob.DeviceOrientations
    <MarshalAs(UnmanagedType.U2)> Public dmPaperSize As PrintJob.PrinterPaperSizes
    Public dmPaperLength As Int16
    Public dmPaperWidth As Int16
    Public dmScale As Int16
    Public dmCopies As Int16
    Public dmDefaultSource As Int16
    Public dmPrintQuality As Int16
    <MarshalAs(UnmanagedType.U2)> Public dmColor As PrintJob.DeviceColourModes
    <MarshalAs(UnmanagedType.U2)> Public dmDuplex As PrintJob.DeviceDuplexSettings
    Public dmYResolution As Int16
    Public dmTTOption As Int16
    Public dmCollate As Int16
    <VBFixedString(32), MarshalAs(UnmanagedType.ByValTStr, SizeConst:=32)> Public dmFormName As String
    Public dmUnusedPadding As Int16
    Public dmBitsPerPel As Int16
    Public dmPelsWidth As Int32
    Public dmPelsHeight As Int32
    Public dmDisplayFlags As Int32
    Public dmDisplayFrequency As Int32

End Class

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and the JOB_INFO_2 defined thus:-

Code:

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<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> _
Friend Class JOB_INFO_2
    Public JobId As Int32
    <MarshalAs(UnmanagedType.LPStr)> Public pPrinterName As String
    <MarshalAs(UnmanagedType.LPStr)> Public pMachineName As String
    <MarshalAs(UnmanagedType.LPStr)> Public pUserName As String
    <MarshalAs(UnmanagedType.LPStr)> Public pDocument As String
    <MarshalAs(UnmanagedType.LPStr)> Public pNotifyName As String
    <MarshalAs(UnmanagedType.LPStr)> Public pDatatype As String
    <MarshalAs(UnmanagedType.LPStr)> Public pPrintProcessor As String
    <MarshalAs(UnmanagedType.LPStr)> Public pParameters As String
    <MarshalAs(UnmanagedType.LPStr)> Public pDriverName As String
    <MarshalAs(UnmanagedType.LPStruct)> Public DeviceMode As DEVMODE
    <MarshalAs(UnmanagedType.LPStr)> Public pStatus As String
    <MarshalAs(UnmanagedType.U4)> Public Status As PrintJob.Print_Job_Statuses
    Public Priority As Int32
    Public Position As Int32
    Public TotalPage As Int32
    Public PagesPrinted As Int32
    <MarshalAs(UnmanagedType.Struct)> Public Submitted As SystemTime
End Class

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Any ideas what I have wrong here? I'm pretty sure the problem is in the DEVMODE class because if I return lpDevMode as an Int32, cast it to an IntPtr and use

Code:

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Marshal.PtrToStructue(lpDevModePtr, dmThis)

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I get the same error.

Thanks in advance,
Duncan

My bad - i was marshalling an Int16 to an enumerated type - but (as any fool knows) these are held internally as Int32 so it doesnae work.

Replaced:

Code:

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<MarshalAs(UnmanagedType.U2)> Public dmOrientation As PrintJob.DeviceOrientations

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With:

Code:

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Private mdmOrientation As Int16

'...
Public ReadOnly Property dmOrientation() As PrintJob.DeviceOrientations
    Get
      Return CType(mdmOrientation, PrintJob.DeviceOrientations)
    End get
End property

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Thanks all,
Duncan

...the OnlyOneGuru...which can resolve his own questions...;)