This class is purely based on Flex3/4, is used for cropping images, arranging partly showing a photo by the user. When cropping, toggle the button on the center stage, then drag to a proper position, then do a cropping, while you can zoom in/out. Features: Easy use for the end user(dragging, zoom in/out),it is wysiwyg. Clean interface for the developer. Pass in the BitmapData,produce a BitmapData.And configuration options for zoom increase step,the crop rectangle.