popupWindow 显示

popupWindow 在控件的各个方向上的显示（上、下、左、右），主要用到popupWindow 的showAtLocation(）方法：

在控件的上方：

 private void showPopUp(View v) {
         LinearLayout layout = new LinearLayout(this);
         layout.setBackgroundColor(Color.GRAY);
         TextView tv = new TextView(this);
         tv.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
         tv.setText("I'm a pop -----------------------------!");
         tv.setTextColor(Color.WHITE);
         layout.addView(tv);

         popupWindow = new PopupWindow(layout,120,120);

         popupWindow.setFocusable(true);
         popupWindow.setOutsideTouchable(true);
         popupWindow.setBackgroundDrawable(new BitmapDrawable());

         int[] location = new int[2];
         v.getLocationOnScreen(location);

         popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0], location[1]-popupWindow.getHeight());
     }

在控件的其他方向上显示只需修改最后一行代码即可，如：

下方：popupWindow.showAsDropDown(v);

左边：

 popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0]-popupWindow.getWidth(), location[1]);

右边：

 popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0]+v.getWidth(), location[1]);