WindowManager.LayoutParams layoutParams = getDialog().getWindow().getAttributes();
layoutParams.dimAmount=0.4f; //设置暗淡值
layoutParams.alpha = 0.3f;//设置透明度
layoutParams.width = WindowManager.LayoutParams.MATCH_PARENT;//设置全屏
layoutParams.height = WindowManager.LayoutParams.MATCH_PARENT;
getDialog().getWindow().setAttributes(layoutParams);