Question

我正在使用Zebra GK420d标签打印机来开发我正在开发的POS应用程序。我试图通过Zebra提供的OPOS驱动程序与打印机进行通信。但是我遇到了麻烦。它是visual basic 2008中的一个简单形式，上面有一个按钮。这是我正在运行的完整代码。

公共类FrameStep1 继承System.Windows.Forms.Form

Private m_Printer As Microsoft.PointOfService.PosPrinter = Nothing

Private Sub ChangeButtonStatus()

    'Disable control.
    btnPrint.Enabled = False
End Sub

Private Sub FrameStep1_Load(ByVal sender As System.Object _
, ByVal e As System.EventArgs) Handles MyBase.Load

    Dim strLogicalName As String
    Dim deviceInfo As DeviceInfo
    Dim posExplorer As PosExplorer

    strLogicalName = "zebra"
    posExplorer = New PosExplorer

    m_Printer = Nothing

    Try
        deviceInfo = posExplorer.GetDevice(DeviceType.PosPrinter, strLogicalName)
        m_Printer = posExplorer.CreateInstance(deviceInfo)

    Catch ex As Exception
        ChangeButtonStatus()
        Return
    End Try

    Try

        m_Printer.Open()
        m_Printer.Claim(1000)
        m_Printer.DeviceEnabled = True

    Catch ex As PosControlException

        ChangeButtonStatus()

    End Try
End Sub


 Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrint.Click

    Try

        m_Printer.PrintNormal(PrinterStation.Receipt, "Hello OPOS for .Net" + vbCrLf)

    Catch ex As PosControlException

    End Try
End Sub

Private Sub FrameStep1_Closing(ByVal sender As Object _
, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

    If m_Printer Is Nothing Then
        Return
    End If

    Try
        m_Printer.DeviceEnabled = False
        m_Printer.Release()
    Catch ex As Exception

    Finally
        m_Printer.Close()

    End Try
End Sub

结束班

你可以看到我调用了claim（）并设置了DeviceEnabled = true。然而，当我调试它时发生的事情是当控件通过m_Printer.Open（）时它神奇地结束于btnPrint_Click（）并且不再继续，除非我单击我的表单上的按钮然后在m_Printer.PrintNormal（）它中断和抛出POSControlException，其中的文本显示“尝试访问必须在使用方法或属性集操作之前声明的专用设备。”

我在这里似乎做错了什么。

Answer 1

你可以试试这个：

if (m_Printer.State == ControlState.Closed)
  { m_Printer.Open();     }           

if (!m_Printer.Claimed)
                   { m_Printer.Claim(0);}

if (!m_Printer.DeviceEnabled)
                   { m_Printer.DeviceEnabled = true;}

Printer.PrintNormal(PrinterStation.Receipt, text);

Printer.CutPaper(100);

另请记住，在开始打印之前，有些ZEBRA打印机会等待切纸器。

通过Zebra OPOS驱动程序与Zebra GK420d进行通信

1 个答案: