VB - how to detect certain words being typed? - vb.net

Question

I have an array that contains the words "hello", "goodbye" and "ok". In VB.NET, how can I write a program that produces a message box every time one of these words is typed in, WITHOUT a button being clicked?
I did some research, and I came across the keypress event - however, this wouldn't be appropriate, because my program would become quite inefficient.
Is there a way in Visual Basic to detect certain words (in this case, in the array) to be detected, instead of just keypress'?

Answer 1

This is how you do it, but it brings about more problems...
Public Class Form1
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
Dim words As String() = TextBox1.Text.Split(" "c)
Dim detectWords As New List(Of String) From {"hello", "goodbye", "ok"}
For Each word As String In words
If detectWords.Contains(word.ToLower) Then
MsgBox(word)
End If
Next
End Sub
End Class
With a keypress event, you could look for the enter key, then process it, instead of each time the text changes...
Public Class Form1
Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
If e.KeyChar = ChrW(Keys.Enter) Then
Dim words As String() = TextBox1.Text.Split(" "c)
Dim detectWords As New List(Of String) From {"hello", "goodbye", "ok"}
For Each word As String In words
If detectWords.Contains(word.ToLower) Then
MsgBox(word)
End If
Next
End If
End Sub
End Class