点击popwindow的时候，计算popwindow的宽度
可能存在需要计算未显示的view的宽度的时候，添加以下代码:

 /**
     * 设置pop的数据源
     */
    public void showViewPopWindow() {
        if (kuaiJieRukouList.size() > 0) {
            int position = 0;
            if (null != kuaiJieRukouList.get(0).getNavcolumns() && !TextUtils.isEmpty(kuaiJieRukouList.get(0).getNavcolumns())) {
                position = Integer.parseInt(kuaiJieRukouList.get(0).getNavcolumns());
            }
            View contentView = LayoutInflater.from(activityContext).inflate(R.layout.home_popwindow_layout, null);
            RecyclerView kuaiJieRecyclerView = (RecyclerView) contentView.findViewById(R.id.webview_recyclerview);
            LinearLayoutManager manager = new LinearLayoutManager(activityContext);
            manager.setOrientation(LinearLayoutManager.VERTICAL);
            kuaiJieRecyclerView.setLayoutManager(manager);
            PopWindowAdapter webViewAdapter = new PopWindowAdapter(activityContext, kuaiJieRukouList, new PopWindowAdapter.PopAdapterListener() {
                @Override
                public void onClick(BusinessEntity entity) {
                    if (mCustomPopWindow != null) {
                        mCustomPopWindow.dissmiss();
                    }
                    StartInfoActivityUtil.homeStartActivity(activityContext, entity.getUrl(), entity.getMenuLittleName(), "快捷入口");
                }
            });

            kuaiJieRecyclerView.setAdapter(webViewAdapter);

            //创建并显示popWindow
            mCustomPopWindow = new CustomPopWindow.PopupWindowBuilder(activityContext)
                    .setView(contentView)
                    .size(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)//显示大小
                    .setFocusable(true)
                    .setOutsideTouchable(true)
                    .create();
        //重点，即可拿到宽高
            contentView.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
            switch (position) {
                //0,1,2,3左上左下右上右下
                case 0:
                case 1:
                    mCustomPopWindow.showAsDropDown(mEntranceImage, mEntranceImage.getWidth(), -kuaiJieRukouList.size() * screenHeight / 20);
                    break;
                case 2:
                case 3:
                    mCustomPopWindow.showAsDropDown(mEntranceImage, -contentView.getMeasuredWidth(), -kuaiJieRukouList.size() * screenHeight / 20);
                    break;
                default:
                    mCustomPopWindow.showAsDropDown(mEntranceImage, mEntranceImage.getWidth(), -kuaiJieRukouList.size() * screenHeight / 20);
                    break;
            }
        } else {
            Toast.makeText(activityContext, "无快捷活动入口", Toast.LENGTH_LONG).show();
        }
    }