Hey,
I'm really stuck and stumped on how to go about fixing this problem.
Essentially, the user enters some text into a RichTextBox(Named Content) and whilst the user is typing, it runs a if loop to see if it matches a word, and if it does, it highlights it.
Here is the code for the Content_TextChanged:

Code:

---

Private Sub Content_TextChanged(sender As Object, e As EventArgs) Handles Content.TextChanged

        Dim words() As String = Content.Text.Split(" ")
     
        For Each word As String In words
            If (word.StartsWith("#")) Then

                HighLight(word, Color.LightGreen)

            ElseIf (word.StartsWith("<")) Then

                HighLight(word, Color.Aquamarine)

            ElseIf (word = "{" Or word = "}" Or word.StartsWith("{") Or word.StartsWith("}") Or word.EndsWith("{") Or word.EndsWith("}")) Then

               
            End If
        Next

    End Sub

---

As you can see, it asks for the sub HighLight:

Code:

---

    Public Sub HighLight(ByVal word As String, ByVal color As Color)
        If (word = "") Then
        Else

            Content.SelectionStart = Content.Find(word)
            Content.SelectionColor = color

            Content.SelectionStart = Content.TextLength
            Content.SelectionLength = 0
            Content.SelectionColor = color.White
        End If

    End Sub

---

The error is thrown when you press Enter on the richtextbox after you have just entered something that has had it's colour changed... if you understand me.
E.G: The user enters "#include" which is changed to the colour Light Green when typing, then the user enters '<stdio.h>' which is changed to Aqua Marine.
So the user has currently only entered: "#include <stdio.h>"
The trouble is when the user hits enter to create a new line, it throws this error:

Quote:

---

An unhandled exception of type 'System.ArgumentOutOfRangeException' occurred in System.Windows.Forms.dll

Additional information: InvalidArgument=Value of '-1' is not valid for 'SelectionStart'.

---

The problem doesn't occur when the user hits space before going onto a new line.
Any help?

Regards,
Josh

Obviously you need to handle the error.

Content.SelectionStart = Content.Find(word)


Try assigning the .Find function to a variable and check it first:

lngWordPos = Content.Find(word)

If lngWordPos < 0 Then
'// Do not bother processing, exit the routine
End If

Hope that helps
G