覆盖Visual Basic标签文本

Question

我正在从收发器读取温度值到串口,我希望这个值改变我的Visual Basic窗体中的标签的值.该值每隔几秒就会改变一次.我使用下面的代码:

Me.dataReceived.Text &= [text]

dataReceived是我正在使用的标签,[text]是我从串口读取的数据.这会导致显示数据,但不会覆盖标签,而是将值相互写入.(附加数据).我试图在=之前删除&但是这没有用,因为没有出现.关于我能做什么的任何想法？

我使用的代码如下:

'To receive data into the text field
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived

    While (SerialPort1.IsOpen)
        ReceivedText(SerialPort1.ReadExisting())    'This is called automatically every time  data is received at the Serial Port
    End While

End Sub

Private Sub ReceivedText(ByVal [text] As String)

    Dim temperature As String

    'This function compares the creating Thread's ID with the calling Thread's ID
    If Me.dataReceived.InvokeRequired Then
        Dim x As New SetTextCallback(AddressOf ReceivedText)
        Me.Invoke(x, New Object() {(text)})
    Else
        'To output to the text box:
        Me.dataReceived.Text = text

        'To output to the label
        temperature = text
        Me.temp.Text = text
        hmd.Text = temperature

    End If
   End Sub

Answer 1

如果要覆盖旧值,则不应使用&=而只是=分配新值:

Me.dataReceived.Text = newText

&= 是相同的 Me.dataReceived.Text = Me.dataReceived.Text & newText

来自MSDN:

的&=运算符连接在其上其左String变量或产权字符串表达式,并将结果指定给在其左侧的变量或属性.