Complete example of conditional datagrid editing dependent upon associated value in row

Example.mxml

<?xml version="1.0"?>
<!-- itemRenderers\events\EndEditEventPreventEdit.mxml -->
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx"
               initialize="init()">
    
    <fx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.collections.ListCollectionView;
            import mx.events.DataGridEvent;
            import mx.events.ListEvent;

            [Bindable]
            private var initDG:ArrayCollection = new ArrayCollection([
                {ID: 0, Artist:'Joe Blow', Album:'Some Record', 
                    Price:5.99},
                {ID: 1, Artist:'Pavement', Album:'Brighten the Corners', 
                    Price:11.99},
                {ID: 2, Artist:'Pavement', Album:'Brighten the Corners', 
                    Price:11.99}
            ]);

            private function disableEditing(event:DataGridEvent):void 
            {
                // get the value in the row that has been triggered
                var item:Object = ListCollectionView(myGrid.dataProvider)
                    .getItemAt(event.rowIndex);

                // get the name of the column being edited
                var colName:String = myGrid.columns[event.columnIndex].dataField;
                
                if(colName == 'Price' && item.ID == 0)
                {  
                    event.preventDefault();
                }
            }

        ]]>
    </fx:Script>
    
    <mx:DataGrid id="myGrid" 
                 dataProvider="{initDG}" 
                 editable="true" 
                 itemEditBeginning="disableEditing(event)" >   
        <mx:columns>
            <mx:DataGridColumn dataField="ID" editable="false"/> <!-- never editable -->
            <mx:DataGridColumn dataField="Artist"/> <!-- always editable -->
            <mx:DataGridColumn dataField="Album"/> <!-- always editable -->
            <mx:DataGridColumn dataField="Price"/> <!-- conditionally editable if associated ID is 0 -->
        </mx:columns>       
    </mx:DataGrid>  
</s:Application>

Also note that if you reorder the columns, the editability rules remain intact.