我正在处理 ZPL 文件，首先我复制原始文件，在新文件中进行一些更改，然后将文件发送到斑马打印机，最后我想删除文件。
除了文件删除，一切都很完美，我明白了The process cannot access the file 'c:\test\Test.lbl' because it is being used by another process.
发送到打印机后如何删除文件？
这是代码：
Private Sub TextBox1_Validating(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox1.Validating
Dim OrigFileName As String = "C:\Test\9320\089.lbl"
Dim DestFileName As String = "c:\test\Test.lbl"
Dim PrinterPath As String = "ZDesigner 110Xi4 600 dpi"
Try
File.Copy(OrigFileName, DestFileName)
File.WriteAllText(DestFileName, File.ReadAllText(DestFileName).Replace("*(A)", TextBox1.Text.Trim()))
File.WriteAllText(DestFileName, File.ReadAllText(DestFileName).Replace("*(B)", "1111111"))
File.WriteAllText(DestFileName, File.ReadAllText(DestFileName).Replace("*(C)", "222222"))
File.WriteAllText(DestFileName, File.ReadAllText(DestFileName).Replace("*(D)", "USA 6"))
' Print the file to the printer.
RawPrinterHelper.SendFileToPrinter(PrinterPath, DestFileName)
Catch ex As Exception
MessageBox.Show("Error: " & ex.Message)
Finally
File.Delete(DestFileName)
End Try
End Sub
这是RawPrinterHelper来自的代码：http: //support.microsoft.com/kb/322090
Public Class RawPrinterHelper
' Structure and API declarions:
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Structure DOCINFOW
<MarshalAs(UnmanagedType.LPWStr)> Public pDocName As String
<MarshalAs(UnmanagedType.LPWStr)> Public pOutputFile As String
<MarshalAs(UnmanagedType.LPWStr)> Public pDataType As String
End Structure
<DllImport("winspool.Drv", EntryPoint:="OpenPrinterW", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function OpenPrinter(ByVal src As String, ByRef hPrinter As IntPtr, ByVal pd As Long) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="ClosePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function ClosePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="StartDocPrinterW", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function StartDocPrinter(ByVal hPrinter As IntPtr, ByVal level As Int32, ByRef pDI As DOCINFOW) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="EndDocPrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function EndDocPrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="StartPagePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function StartPagePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="EndPagePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function EndPagePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="WritePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function WritePrinter(ByVal hPrinter As IntPtr, ByVal pBytes As IntPtr, ByVal dwCount As Int32, ByRef dwWritten As Int32) As Boolean
End Function
' SendBytesToPrinter()
' When the function is given a printer name and an unmanaged array of
' bytes, the function sends those bytes to the print queue.
' Returns True on success or False on failure.
Public Shared Function SendBytesToPrinter(ByVal szPrinterName As String, ByVal pBytes As IntPtr, ByVal dwCount As Int32) As Boolean
Dim hPrinter As IntPtr ' The printer handle.
Dim dwError As Int32 ' Last error - in case there was trouble.
Dim di As DOCINFOW ' Describes your document (name, port, data type).
Dim dwWritten As Int32 ' The number of bytes written by WritePrinter().
Dim bSuccess As Boolean ' Your success code.
' Set up the DOCINFO structure.
With di
.pDocName = "My Visual Basic .NET RAW Document"
.pDataType = "RAW"
End With
' Assume failure unless you specifically succeed.
bSuccess = False
If OpenPrinter(szPrinterName, hPrinter, 0) Then
If StartDocPrinter(hPrinter, 1, di) Then
If StartPagePrinter(hPrinter) Then
' Write your printer-specific bytes to the printer.
bSuccess = WritePrinter(hPrinter, pBytes, dwCount, dwWritten)
EndPagePrinter(hPrinter)
End If
EndDocPrinter(hPrinter)
End If
ClosePrinter(hPrinter)
End If
' If you did not succeed, GetLastError may give more information
' about why not.
If bSuccess = False Then
dwError = Marshal.GetLastWin32Error()
End If
Return bSuccess
End Function ' SendBytesToPrinter()
' SendFileToPrinter()
' When the function is given a file name and a printer name,
' the function reads the contents of the file and sends the
' contents to the printer.
' Presumes that the file contains printer-ready data.
' Shows how to use the SendBytesToPrinter function.
' Returns True on success or False on failure.
Public Shared Function SendFileToPrinter(ByVal szPrinterName As String, ByVal szFileName As String) As Boolean
' Open the file.
Dim fs As New FileStream(szFileName, FileMode.Open)
' Create a BinaryReader on the file.
Dim br As New BinaryReader(fs)
' Dim an array of bytes large enough to hold the file's contents.
Dim bytes(fs.Length) As Byte
Dim bSuccess As Boolean
' Your unmanaged pointer.
Dim pUnmanagedBytes As IntPtr
' Read the contents of the file into the array.
bytes = br.ReadBytes(fs.Length)
' Allocate some unmanaged memory for those bytes.
pUnmanagedBytes = Marshal.AllocCoTaskMem(fs.Length)
' Copy the managed byte array into the unmanaged array.
Marshal.Copy(bytes, 0, pUnmanagedBytes, fs.Length)
' Send the unmanaged bytes to the printer.
bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, fs.Length)
' Free the unmanaged memory that you allocated earlier.
Marshal.FreeCoTaskMem(pUnmanagedBytes)
Return bSuccess
End Function ' SendFileToPrinter()
' When the function is given a string and a printer name,
' the function sends the string to the printer as raw bytes.
Public Shared Function SendStringToPrinter(ByVal szPrinterName As String, ByVal szString As String)
Dim pBytes As IntPtr
Dim dwCount As Int32
' How many characters are in the string?
dwCount = szString.Length()
' Assume that the printer is expecting ANSI text, and then convert
' the string to ANSI text.
pBytes = Marshal.StringToCoTaskMemAnsi(szString)
' Send the converted ANSI string to the printer.
SendBytesToPrinter(szPrinterName, pBytes, dwCount)
Marshal.FreeCoTaskMem(pBytes)
End Function
结束类