safehandle

问题 I am trying to send ZPL commands to a Zebra ZT230 printer. The printer and drivers are installed and the printer port is "USB003". The PC communicates perfectly with the printer via either Zebra Printer Setup Utilities or ZebraDesign. I tried the following code: Private Declare Function CreateFile Lib "kernel32.dll" (ByVal lpFileName As String, ByVal dwDesiredAccess As FileAccess, _ ByVal dwShareMode As UInteger, ByVal lpSecurityAttributes As IntPtr, ByVal dwCreationDisposition As FileMode, _

问题 I am trying to send ZPL commands to a Zebra ZT230 printer. The printer and drivers are installed and the printer port is "USB003". The PC communicates perfectly with the printer via either Zebra Printer Setup Utilities or ZebraDesign. I tried the following code: Private Declare Function CreateFile Lib "kernel32.dll" (ByVal lpFileName As String, ByVal dwDesiredAccess As FileAccess, _ ByVal dwShareMode As UInteger, ByVal lpSecurityAttributes As IntPtr, ByVal dwCreationDisposition As FileMode, _