请问VB.NET中怎么获取当前打印机的纸张类型

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms

Imports System.Security
Imports System.Drawing.Printing
Imports System.Runtime.InteropServices

Public Class Form1
    Private Const PRINTER_ENUM_LOCAL As Integer = 2
    Private Const PRINTER_ENUM_CONNECTIONS As Integer = 4
    Private Const DC_PAPERNAMES As Integer = 16
    Private Const DC_PAPERS As Integer = 2
    Private Const DC_PAPERSIZE As Integer = 3
    Private Const DC_BINNAMES As Integer = 12

    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
      Private Structure PRINTER_INFO_5
        <MarshalAs(UnmanagedType.LPTStr)> _
        Public PrinterName As String

        <MarshalAs(UnmanagedType.LPTStr)> _
        Public PortName As String

        <MarshalAs(UnmanagedType.U4)> _
        Public Attributes As Int32

        <MarshalAs(UnmanagedType.U4)> _
        Public DeviceNotSelectedTimeout As Int32

        <MarshalAs(UnmanagedType.U4)> _
        Public TransmissionRetryTimeout As Int32

    End Structure

 

    <DllImport("winspool.drv", EntryPoint:="DeviceCapabilitiesA", SetLastError:=True)> _
    Public Shared Function DeviceCapabilities( _
           ByVal device As String, _
           ByVal port As String, _
           ByVal capability As Int16, _
           ByVal outputBuffer As IntPtr, _
           ByVal deviceMode As IntPtr) As Int32
    End Function

    <DllImport("winspool.drv", SetLastError:=True)> _
    Public Shared Function EnumPrintersW(ByVal flags As Int32, _
           ByVal printerName As String, _
           ByVal level As Int32, ByVal buffer As IntPtr, ByVal bufferSize As Int32, ByRef _
           requiredBufferSize As Int32, ByRef numPrintersReturned As Int32) As Boolean
    End Function

    <DllImport("kernel32.dll", EntryPoint:="GetLastError", SetLastError:=False, _
            ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall), _
    SuppressUnmanagedCodeSecurityAttribute()> _
    Public Shared Function GetLastError() As Int32

    End Function

 

    Public Shared Sub GetDefinedPapers(ByVal printerName As String)
        Dim info5 As PRINTER_INFO_5
        Dim PRINT_INFO As PRINTER_INFO_5 = Nothing
        Dim requiredSize As Integer
        Dim numPrinters As Integer
        Dim intI As Integer
        Dim foundPrinter As Boolean = EnumPrintersW(PRINTER_ENUM_LOCAL + PRINTER_ENUM_CONNECTIONS, _
                   String.Empty, 5, IntPtr.Zero, 0, requiredSize, numPrinters)
        Dim info5Size As Integer = requiredSize
        Dim info5Ptr As IntPtr = Marshal.AllocHGlobal(info5Size)
        Dim buffer As IntPtr = IntPtr.Zero

        Try

            foundPrinter = EnumPrintersW(PRINTER_ENUM_LOCAL + PRINTER_ENUM_CONNECTIONS, _
                   String.Empty, 5, info5Ptr, info5Size, requiredSize, numPrinters)

            Dim port As String = Nothing

            For intI = 0 To numPrinters - 1
                info5 = Marshal.PtrToStructure(CType(Integer.Parse(intI * Marshal.SizeOf(PRINT_INFO.GetType)) + CType(info5Ptr, Int32), IntPtr), PRINT_INFO.GetType)

                If info5.PrinterName = printerName Then
                    port = info5.PortName
                    Exit For
                End If

            Next

            Dim numNames As Integer
            numNames = DeviceCapabilities(printerName, port, DC_PAPERNAMES, IntPtr.Zero, IntPtr.Zero)

            If (numNames < 0) Then
                Dim errorCode As Integer = GetLastError()
                Console.WriteLine("Number of names = {1}: {0}", errorCode, numNames)
                Return
            End If

            buffer = Marshal.AllocHGlobal(numNames * 64)

            numNames = DeviceCapabilities(printerName, port, DC_PAPERNAMES, buffer, IntPtr.Zero)

            If numNames < 0 Then
                Dim errorCode As Integer = GetLastError()
                Console.WriteLine("Number of names = {1}: {0}", errorCode, numNames)
                Return
            End If

            Dim names(numNames - 1) As String

            For intI = 0 To numNames - 1
                names(intI) = Marshal.PtrToStringAnsi(CType((intI * 64) + CType(buffer, Integer), IntPtr))
            Next

            Marshal.FreeHGlobal(buffer)

            buffer = IntPtr.Zero

            Dim numPapers As Integer = DeviceCapabilities(printerName, port, DC_PAPERS, IntPtr.Zero, IntPtr.Zero)

            If numPapers < 0 Then
                Console.WriteLine("No papers")
                Return
            End If

 

            buffer = Marshal.AllocHGlobal(numPapers * 2)

            numPapers = DeviceCapabilities(printerName, port, DC_PAPERS, buffer, IntPtr.Zero)

            If numPapers < 0 Then

                Console.WriteLine("No papers")

                Return

            End If

            Dim kinds(numPapers - 1) As String

            For intI = 0 To numPapers - 1
                kinds(intI) = Marshal.ReadInt16(buffer, intI * 2)
            Next

            For intI = 0 To numPapers - 1
                Console.WriteLine("Paper {0} : {1}", kinds(intI), names(intI))
            Next

            Dim numPaperboxs As Integer = DeviceCapabilities(printerName, port, DC_BINNAMES, IntPtr.Zero, IntPtr.Zero)

            If numPaperboxs < 0 Then
                Console.WriteLine("No papers")
                Return
            End If

 

            buffer = Marshal.AllocHGlobal(numPapers * 2)

            numPaperboxs = DeviceCapabilities(printerName, port, DC_BINNAMES, buffer, IntPtr.Zero)

            If numPaperboxs < 0 Then

                Console.WriteLine("No papers")

                Return

            End If

            Dim arrBoxsNm(numPaperboxs - 1) As String

            For intI = 0 To numPaperboxs - 1
                arrBoxsNm(intI) = Marshal.PtrToStringAnsi(CType((intI * 24) + CType(buffer, Integer), IntPtr))
            Next

            For intI = 0 To numPaperboxs - 1
                Console.WriteLine("PaperboxNm {0}", arrBoxsNm(intI))
            Next

        Finally
            Marshal.FreeHGlobal(info5Ptr)
        End Try
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        GetDefinedPapers("//Print/Canon LASER SHOT LBP-1420")
    End Sub
End Class