Refactor btnLink enabling logic by profile type

EnableBtnLink() now enables/disables btnLink based on the selected profile's type, applying specific logic for "db", "activedirectory", "xml", and "fulltext". The method is also called after regex and XML tree changes to keep the button state in sync with the UI.

ToolCollection/frmNIVerknuepfungen.vb

@@ -1396,9 +1396,30 @@ Public Class frmNIVerknuepfungen
     End Function
 
     Private Sub EnableBtnLink()
+        If Me._selectedProfil Is Nothing Then
+            btnLink.Enabled = False
+            Return
+        End If
+
+        Select Case Me._selectedProfil.Ni_Art
+            Case "db", "activedirectory"
                 btnLink.Enabled =
                 lbxWMIndex.SelectedItems.Count > 0 And
                 (lbxQuelle1.SelectedItems.Count > 0 OrElse txtManIndexwert.Text <> "")
+
+            Case "xml"
+                btnLink.Enabled =
+                lbxWMIndex.SelectedItems.Count > 0 And
+                (trvwxml.SelectedNode IsNot Nothing OrElse txtManIndexwert.Text <> "")
+
+            Case "fulltext"
+                btnLink.Enabled =
+                lbxWMIndex.SelectedItems.Count > 0 And
+                (txtregex.Text <> "" OrElse txtManIndexwert.Text <> "")
+
+            Case Else
+                btnLink.Enabled = False
+        End Select
     End Sub
 
     Private Sub btnLink_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLink.Click
@@ -3463,6 +3484,7 @@ Public Class frmNIVerknuepfungen
             End If
 
         End If
+        EnableBtnLink()
         'Catch ex As Exception
         '    MsgBox("Fehler bei Check Änderung Regex:" & vbNewLine & vbNewLine & ex.Message, MsgBoxStyle.Critical)
         'End Try
@@ -3611,8 +3633,7 @@ Public Class frmNIVerknuepfungen
     End Sub
 
     Private Sub trvwxml_AfterSelect(sender As Object, e As TreeViewEventArgs) Handles trvwxml.AfterSelect
-
-
+        EnableBtnLink()
     End Sub
 
     Private Sub tabctrlbottom_SelectedIndexChanged(sender As Object, e As EventArgs) Handles tabctrlbottom.SelectedIndexChanged