Flex mobile 如何attachCamera

 import mx.events.FlexEvent; 
 
import org.osmf.net.StreamType; 
 
import spark.components.mediaClasses.DynamicStreamingVideoItem; 
import spark.components.mediaClasses.DynamicStreamingVideoSource; 
 
private var _cam:DynamicStreamingVideoSource =  new DynamicStreamingVideoSource(); 
private var _dynVideoSource:DynamicStreamingVideoSource; 
 
protected function application1_creationCompleteHandler(event:FlexEvent):void 
{ 
 
    _dynVideoSource=new DynamicStreamingVideoSource(); 
 
    var videoItems:Vector.<DynamicStreamingVideoItem>; 
    videoItems=new Vector.<DynamicStreamingVideoItem>(); 
    videoItems[0]=new DynamicStreamingVideoItem(); 
 
    _dynVideoSource.host= ""; 
    _dynVideoSource.streamType=StreamType.LIVE; 
    _dynVideoSource.streamItems=videoItems; 
 
    mycam.source=_dynVideoSource; 
 
    var cam:Camera = Camera.getCamera(); //Camera.names[0]); 
    cam.setMode(640, 480, 15); 
    cam.setQuality(0, 80); 
    mycam.videoObject.attachCamera(cam);  
}