VB上位机问题 给定的端口名称未以 COM/com 开头或未解析为有效的串行端口

调试舵机用的上位机
临时抱佛脚 求大神指点
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Text = "串口上位机（舵机调试用）："
Label1.Text = "串口选择"
Label2.Text = "波特率"
Button1.Text = "打开串口"
Button2.Text = "关闭串口"

End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
    If ComboBox1.Text = "COM4" Then
        SerialPort1.PortName = 4
    ElseIf ComboBox1.Text = "COM9" Then
        SerialPort1.PortName = 9
    ElseIf ComboBox1.Text = "COM10" Then
        SerialPort1.PortName = 10
    End If


End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
    SerialPort1.Close() '关闭串口
End Sub

Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox2.SelectedIndexChanged
    If ComboBox2.Text = "9600" Then
        SerialPort1.BaudRate = 9600
        SerialPort1.DataBits = 8
        SerialPort1.StopBits = 1
        SerialPort1.RtsEnable = True

    ElseIf ComboBox2.Text = "19200" Then
        SerialPort1.BaudRate = 19200
        SerialPort1.DataBits = 8
        SerialPort1.StopBits = 1
        SerialPort1.RtsEnable = True
    ElseIf ComboBox2.Text = "115200" Then
        SerialPort1.BaudRate = 115200
        SerialPort1.DataBits = 8
        SerialPort1.StopBits = 1
        SerialPort1.RtsEnable = True
    End If
End Sub

Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label1.Click

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    SerialPort1.Open() '打开串口

End Sub

End Class

看看你的计算机是否有com4 com9 com10