Close form in DataRecieved event - vb.net

Question

i have form that captures a hex code from a serial port. i want to close the form as soon as the hex is captured. but i get an error and cant close the form from DataReceived event.
my code :
Public hex As String
Dim sp As SerialPort
Private Sub SerialPort1_DataReceived(sender As Object, e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Dim t_hex As String = sp.ReadLine()
If Len(t_hex) < 21 Then
Exit Sub
End If
t_hex = Mid(t_hex, 11, 11)
hex = t_hex
sp.Close()
Me.Close() '' ERROR LINE
End Sub
the error :
An unhandled exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll
Additional information: Cross-thread operation not valid: Control 'Dlg_CardRead' accessed from a thread other than the thread it was created on.
what is the correct way of approaching this and closing the form ?
thanks

Answer 1

found the answer :
Public hex As String
Dim sp As SerialPort
Private Sub SerialPort1_DataReceived(sender As Object, e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Dim t_hex As String = sp.ReadLine()
If Len(t_hex) < 21 Then
Exit Sub
End If
t_hex = Mid(t_hex, 11, 11)
hex = t_hex
sp.Close()
CloseMe()
End Sub
Private Sub CloseMe()
If Me.InvokeRequired Then
Me.Invoke(New MethodInvoker(AddressOf CloseMe))
Exit Sub
End If
Me.Close()
End Sub
EDIT :
the problem with the first code was that i was calling methods from Win Forms thread inside another thread. so in another words DataReceived event runs in another thread and turns out i can't use Me.Close() inside that thread.
The InvokeRequired property returns true if you are on any thread other than the UI thread, and the Invoke method invokes the given method from the UI thread.