大家想必對PopupWindow不會很陌生吧澳眷，我們在開發(fā)中經(jīng)常會遇到要求使其背景半透明的需求，但網(wǎng)上的很多解決方案只能是在大部分機型上滿足要求甫题，像華為這樣的機型就會發(fā)現(xiàn)我們原來設置的背景變暗效果的代碼并沒有起效果派敷。
這里我貼出最終的兼容方案：

View contentView;
    LayoutInflater mLayoutInflater = LayoutInflater.from(activity);
    contentView = mLayoutInflater.inflate(R.layout.layout_popupwindow,
            null);
    pop = new PopupWindow(contentView,
            ViewGroup.LayoutParams.MATCH_PARENT, (int) context.getResources().getDimension(R.dimen.y568));
    TextView tvTitle = (TextView) contentView.findViewById(R.id.text);
    tvTitle.setText(strTitle);
    ListView listView = (ListView) contentView.findViewById(R.id.list);
    // 產(chǎn)生背景變暗效果
    WindowManager.LayoutParams lp = activity.getWindow()
            .getAttributes();
    lp.alpha = 0.4f;
    activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
    activity.getWindow().setAttributes(lp);
    pop.setTouchable(true);
    pop.setFocusable(true);
    pop.setBackgroundDrawable(new BitmapDrawable());
    pop.setOutsideTouchable(true);
    pop.showAtLocation(contentView, Gravity.BOTTOM, 0, 0);
    pop.update();
    pop.setOnDismissListener(new PopupWindow.OnDismissListener() {

        // 在dismiss中恢復透明度
        public void onDismiss() {
            WindowManager.LayoutParams lp = activity.getWindow()
                    .getAttributes();
            lp.alpha = 1f;
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
            activity.getWindow().setAttributes(lp);
        }
    });
    listView.setOnItemClickListener(onItemClickListener);
    listView.setAdapter(adapter);

注：特別是下面幾行代碼

// 產(chǎn)生背景變暗效果
    WindowManager.LayoutParams lp = activity.getWindow()
            .getAttributes();
    lp.alpha = 0.4f;
    activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
    activity.getWindow().setAttributes(lp);
    pop.setTouchable(true);
    pop.setFocusable(true);
    pop.setBackgroundDrawable(new BitmapDrawable());
    pop.setOutsideTouchable(true);
    pop.showAtLocation(contentView, Gravity.BOTTOM, 0, 0);
    pop.update();
    pop.setOnDismissListener(new PopupWindow.OnDismissListener() {

        // 在dismiss中恢復透明度
        public void onDismiss() {
            WindowManager.LayoutParams lp = activity.getWindow()
                    .getAttributes();
            lp.alpha = 1f;
              activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
            activity.getWindow().setAttributes(lp);
        }
    });

網(wǎng)上很多方案都要求加下面這兩行代碼，但其實加上反而會影響華為這種機型的顯示效果

ColorDrawable dw = new ColorDrawable(-00000);
popupWindow.setBackgroundDrawable(dw);