vb.net - 当我的条形码扫描仪扫描条形码时，我的 textbox1 将收到 System.Windows.Forms.TextBox, Text: 错误消息。有人能帮我吗

Question

当我的条形码扫描仪扫描条形码时，在我的文本框中，我会得到

System.Windows.Forms.TextBox，文本：错误消息。

我尝试了很多方法来解决这个问题，但仍然没有成功。有人可以帮我看看吗？谢谢

下面是我的代码

Public Class Form1
    Dim dataIn As String
    'Dim userText As String

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        SerialPort.PortName = "COM1"
        SerialPort.BaudRate = CInt("9600")
        SerialPort.Parity = Parity.None
        SerialPort.StopBits = StopBits.One
        SerialPort.Handshake = Handshake.None
        SerialPort.Open()
        SerialPort.ReadTimeout = 200

        If SerialPort.IsOpen Then
            ' TextBox1.Text = ""
        End If
    End Sub

    Private Sub SerialPort_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived

        dataIn = SerialPort.ReadExisting
        dataIn = TextBox1.Text
        TextBox1.Text += SerialPort.ReadExisting().ToString()
        SetText(TextBox1.ToString())

    End Sub
    Delegate Sub SetTextCallback(ByVal text As String)

    Private Sub SetText(ByVal text As String)
        If Me.TextBox1.InvokeRequired Then
            Dim d As SetTextCallback = New SetTextCallback(AddressOf SetText)
            Me.Invoke(d, New Object() {text})
        Else
            Me.TextBox1.Text = text.ToString
        End If
    End Sub

标签： vb.net

Answer 1

您不能设置所有这些属性并使用没有SerialPort.

我不熟悉串口代码，但我怀疑事件中sender的DataReceived是串口。所以只需投射sender到SerialPort. 调用ReadExisting返回字符串的方法并将其分配.Text给TextBox.

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim sp As New SerialPort()
    sp.PortName = "COM1"
    sp.BaudRate = CInt("9600")
    sp.Parity = Parity.None
    sp.StopBits = StopBits.One
    sp.Handshake = Handshake.None
    sp.Open()
    sp.ReadTimeout = 200
End Sub

Private Sub SerialPort_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived
    TextBox1.Text += DirectCast(sender, SerialPort).ReadExisting
End Sub

您还需要在某个地方处理端口。