PopWindow

   初始化PopWindow

View mPopupMenu =
				LayoutInflater.from(this).inflate(R.layout.popupmenu, null);


		mPopupWindow =
				new PopupWindow(mPopupMenu, (int) (getDensityRatio() * 90),
						(int) (getDensityRatio() * 180));                                                                                           popwindow显示位置  mLinkagePopWindow.showAtLocation(parentView, Gravity.BOTTOM|Gravity.CENTER_HORIZONTAL, 0, 0);  //第一个参数代表父 view 第二个参数代表 显示在父view的底部