If you port your TX Text Control ActiveX application to .NET you may miss the FieldAtInputPos property, which returns a field identifier, if there is a field at the current caret position.

This property has been implemented with the TextFieldCollection.GetItem() method: It gets the text field at the current input position or returns null, if there is no text field at this position.

Dim curField As TXTextControl.TextField = TextControl1.TextFields.GetItem()
If curField Is Nothing Then
    MsgBox("No field at input position")
    MsgBox("There is a field at this position: " + curField.Text)
End If

This should not be used to check whether you can insert a field at this position or not.

To do this, TX Text Control offers the TextFieldCollection.CanAdd property that returns false, if the field cannot be inserted at the current position. This can be used to enable a button in a button bar or a menu entry that lets the user change field attributes of the current field.