Winform VB.net在richtextbox中检测字符串时如何弹出msgbox是/否

我正在开发使用串行通信进行数据传输的软件。我的问题与richtextbox有关，当richtextbox中出现“更改配置？”一词时，我想弹出一个InputBox

请帮帮我

这是我的配置：

    Private Sub btnWrEr_Click(sender As Object, e As EventArgs) Handles btnWrEr.Click
    SerialPort1.WriteLine("write erase" & vbCr & vbCr & "reload" & vbCr)
    If InStr(rtbReceived.Text, "System configuration has been modified. Save? [yes/no]:") Then
        Dim save As String
        save = InputBox("System configuration has been modified. Save? [yes/no]:", "yes/no")
        SerialPort1.WriteLine(save & vbCr)
    Else
        SerialPort1.Write(vbCr)
    End If
End Sub

这是我的rtb接收编码：

Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
    ReceivedText(SerialPort1.ReadExisting())
End Sub


Private Sub ReceivedText(ByVal [text] As String)
    If Me.rtbReceived.InvokeRequired Then
        Dim x As New SetTextCallBack(AddressOf ReceivedText)
        Me.Invoke(x, New Object() {(text)})
    Else
        Me.rtbReceived.Text &= [text]
    End If

End Sub

Private Sub rtbReceived_TextChanged(sender As Object, e As EventArgs) Handles rtbReceived.TextChanged
    rtbReceived.SelectionStart = rtbReceived.TextLength
    rtbReceived.ScrollToCaret()
End Sub

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这看起来非常简单，只需将此代码添加到文本更改事件中即可

    If RichTextBox1.Text.Contains("change configuration ?") Then
        InputString = InputBox("How do you want to change it?")
    End If

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或者不使用if..end if语句中的行，只需调用另一个子节点

请上传您尝试的内容