android popupwindow位置显示

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());
}

popupWindow.showAsDropDown(v);

int[] location = new int[2];
v.getLocationOnScreen(location);
popupWindow.showAtLocation(v, Gravity.TOP, 0,location[1]+v.getHeight());

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

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