用Flex3自带ImageSnapShot实现打印预览

<?xml version="1.0"?>
<!-- DataGrid control example. -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
    <mx:Script>
        <![CDATA[
            import mx.graphics.ImageSnapshot;
            import mx.core.UIComponent;
            private function print(u:UIComponent):void{
                var bmp:BitmapData = ImageSnapshot.captureBitmapData(u);
                var i:Bitmap = new Bitmap(bmp);                
                img.source = i;
                img.scaleContent = true;
                tn.selectedIndex = 1;
            }
        ]]>
    </mx:Script>
    <mx:XMLList id="employees">
        <employee>
            <name>Christina Coenraets</name>
            <phone>555-219-2270</phone>
            <email>[e-mail]</email>
            <active>true</active>
        </employee>
        <employee>
            <name>Joanne Wall</name>
            <phone>555-219-2012</phone>
            <email>[e-mail]</email>
            <active>true</active>
        </employee>
        <employee>
            <name>Maurice Smith</name>
            <phone>555-219-2012</phone>
            <email>[e-mail]</email>
            <active>false</active>
        </employee>
        <employee>
            <name>Mary Jones</name>
            <phone>555-219-2000</phone>
            <email>[e-mail]</email>
            <active>true</active>
        </employee>
    </mx:XMLList>
<mx:TabNavigator id="tn" width="100%" height="100%" creationPolicy="all">
    

    <mx:Panel title="Panel" label="Example" height="100%" width="100%"
        paddingTop="10" paddingLeft="10" paddingRight="10" id="p1">

        <mx:Label width="100%" color="blue"
            text="Select a row in the DataGrid control."/>

        <mx:DataGrid id="dg" width="100%" height="100%" rowCount="5" dataProvider="{employees}">
            <mx:columns>
                <mx:DataGridColumn dataField="name" headerText="Name"/>
                <mx:DataGridColumn dataField="phone" headerText="Phone"/>
                <mx:DataGridColumn dataField="email" headerText="Email"/>
            </mx:columns>
        </mx:DataGrid>

        <mx:Form width="100%" height="100%">
            <mx:FormItem label="Name">
                <mx:Label text="{dg.selectedItem.name}"/>
            </mx:FormItem>
            <mx:FormItem label="Email">
                <mx:Label text="{dg.selectedItem.email}"/>
            </mx:FormItem>
            <mx:FormItem label="Phone">
                <mx:Label text="{dg.selectedItem.phone}"/>
            </mx:FormItem>
        </mx:Form>
        
    </mx:Panel>
    <mx:Panel title="PrintPreview" label="Preview" height="100%" width="100%"
        paddingTop="10" paddingLeft="10" paddingRight="10">
        <mx:Image id="img" />
     </mx:Panel>
    
</mx:TabNavigator>
    <mx:ControlBar width="606">
        <mx:Button label="Print DataGrid" click="print(dg)"/>
        <mx:Button label="Print Panel" click="print(p1)"/>
        <mx:Button label="Print Application" click="print(this)"/>
    </mx:ControlBar>
</mx:Application>