如何获得打印机的句柄？？

[wlfei]

我想用vb 6.0编写的控件，该控件的其中一个方法是要调用打印机的指针。我不知道现在如何才能获得打印机的指针？？？？
请教各位高手，谢谢了！

[allanli]

Public Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA" _
(ByVal pPrinterName As String, ByRef phPrinter As Int32, ByVal pDefault As Int32) As Boolean


Dim PrinterHandle As Long ' Handle to printer

OpenPrinter(PrinterName, PrinterHandle, 0&) 'PrinterHandle is what U want

[wlfei]

Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Dim printer As New Printing.PrinterSettings
printer.PrinterName = "Adobe PDF"
PrintDocument1.PrinterSettings = printer
PrintDocument1.Print()

End Sub

Private Sub PrintDocument1_PrintPage(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
MsgBox("调用打印")

MapDisp.OutputMap(e.Graphics.GetHdc.ToInt32)

End Sub


错误提示如下：
未处理的“System.InvalidOperationException”类型的异常出现在 system.drawing.dll 中。

其他信息: 该对象当前正在其他地方使用。

其中MapDisp就是用vb 6.0编写的控件。
不知道上面的代码到底存在什么问题？？？？？？
请教各位高手了，谢谢！