Dim myLayerCollection As ESRI.ArcGIS.Client.LayerCollection = MyMap.Layers 'Dim myLayerCount As Double = myLayerCollection.Count 'MessageBox.Show("Number of Layers in the Map:" + myLayerCount.ToString) Dim fl As FeatureLayer For Each l In myLayerCollection If TypeOf (l) Is FeatureLayer Then fl = l fl.Visible = False End If Next