绘制圆形图片

        /** 
         * 根据原图和变长绘制圆形图片 
         *  wyn
         * @param source 
         * @param min 
         * @return 
         */  
        private static Bitmap createCircleImage(Bitmap source, int min)  
        {  
           Paint paint = new Paint();  
            paint.setAntiAlias(true);   
            Bitmap target = Bitmap.createBitmap(min, min, Bitmap.Config.ARGB_8888);  
            /** 
             * 产生一个同样大小的画布 
             */  
            Canvas canvas = new Canvas(target);  
            /** 
             * 首先绘制圆形 
             */  
            canvas.drawCircle(min / 2, min / 2, min / 2, paint);  
            /** 
             * 使用SRC_IN 
             */  
            paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));  
            /** 
             * 绘制图片 
             */  
            canvas.drawBitmap(source, 0, 0, paint); 
            /**
            *绘制圆形 
            */
            /*
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeWidth(6);
            paint.setColor(Color.GRAY);
            canvas.drawCircle(min / 2, min / 2, min / 2, paint);
            */
            return target;  
        }