<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" viewSourceURL="srcview/index.html">
    
    <mx:Canvas
        id="canvas"
        width="50%"
        height="50%"
        horizontalCenter="0"
        verticalCenter="0"
        >
        <!--
            you seem to have to set horizontalScrollPolicy and 
            verticalScrollPolicy to on in order to get the 
            lockedColumnCount to work
        -->
        <mx:DataGrid
            width="{canvas.width}"
            height="100%"
            verticalScrollPolicy="on"
            horizontalScrollPolicy="on"
            lockedColumnCount="3"
            >
            <mx:columns>
                <mx:DataGridColumn
                    headerText="Name"
                    width="180"
                    minWidth="180"
                    />
                <mx:DataGridColumn
                    headerText="Grade"
                    width="50"
                    minWidth="50"
                    />
                <mx:DataGridColumn
                    headerText="Data"
                    width="60"
                    minWidth="60"
                    />
                <mx:DataGridColumn
                    headerText="Test 1"
                    width="110"
                    minWidth="110"
                    />
                <mx:DataGridColumn
                    headerText="Test 2"
                    width="110"
                    minWidth="110"
                    />
                <mx:DataGridColumn
                    headerText="Test 3"
                    width="110"
                    minWidth="110"
                    />
                <mx:DataGridColumn
                    headerText="Test 4"
                    width="110"
                    minWidth="110"
                    />
                <mx:DataGridColumn
                    headerText="Test 5"
                    width="110"
                    minWidth="110"
                    />
                <mx:DataGridColumn
                    headerText="Test 6"
                    width="110"
                    minWidth="110"
                    />
                    
            </mx:columns>
        </mx:DataGrid>
    </mx:Canvas>
        
</mx:Application>