android 图片视图居中

LinearLayout dragView = new LinearLayout(mContext);
            dragView.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT,
                    LayoutParams.FILL_PARENT, Gravity.CENTER));
            dragView.setGravity(Gravity.CENTER);
            ImageView imageView = new ImageView(mContext);
            imageView.setScaleType(ScaleType.CENTER_INSIDE);
            dragView.addView(imageView);