點擊顯示popupWindow背景切換透明，popupWindow消失背景恢復

private void bgAlpha(float bgAlpha) {

WindowManager.LayoutParams lp = getWindow().getAttributes();

lp.alpha = bgAlpha;//0.0-1.0

? ? getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);

getWindow().setAttributes(lp);

點擊顯示popupWindow時調用

bgAlpha(0.5f);

popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {

@Override

? ? public void onDismiss() {

bgAlpha(1f);

? ? }

});