VB.Net串口数据未触发VS2019

Imports System.IO.Ports

Public Class Form1
    Private WithEvents serialPort As New SerialPort("COM1", 9600)

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 设置串口参数
        serialPort.BaudRate = 9600
        serialPort.DataBits = 8
        serialPort.StopBits = StopBits.One
        serialPort.Parity = Parity.None

        ' 打开串口
        serialPort.Open()
    End Sub

    Private Sub serialPort_DataReceived(sender As Object, e As SerialDataReceivedEventArgs) Handles serialPort.DataReceived
        ' 处理接收到的数据
        Dim data As String = serialPort.ReadExisting()
        ' TODO: 进行数据处理操作
    End Sub

    Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        ' 关闭串口
        serialPort.Close()
    End Sub
End Class