在recyclerview中滚动到特定类别位置

Question

我想在加载recyclerview之后滚动到项目ID == 5,我直接设置项目ID setTargetPosition....如果有任何人有更好的线索,请帮助我.根据响应我想在加载recyclerview后直接滚动到三明治类别....

这是我的setAdapter代码;

                try {
                JSONArray jsonArray = arrayList.get(0);
                for (int i = 0; i < jsonArray.length(); i++) {
                    JSONObject jObj = jsonArray.getJSONObject(i);
                    String catName = jObj.getString("CategoryName");
                    String catId = jObj.getString("CategoryID");
                    Category cat1 = createCategory(catName, Integer.parseInt(catId));
                    JSONArray jProductDetails = jObj.getJSONArray("ProductDetails");
                    ArrayList<HashMap<String, String>> productdetaildata = new ArrayList<HashMap<String, String>>();
                    for (int j = 0; j < jProductDetails.length(); j++) {
                        JSONObject jP = jProductDetails.getJSONObject(j);
                        HashMap<String, String> map = new HashMap<String, String>();
                        map.put(HitUtilities.product_id, jP.getString("ProductID"));
                        map.put(HitUtilities.product_name, jP.getString("ProductName"));
                        map.put(HitUtilities.product_image, jP.getString("PhotoImagePath"));
                        map.put(HitUtilities.product_price, jP.getString("CurrentPrice"));
                        map.put(HitUtilities.product_isFavorite, jP.getString("Favorited"));
                        productdetaildata.add(map);
                    }
                    cat1.setItemList(createItems(productdetaildata, jProductDetails.length()));
                    catList.add(cat1);
                }

                restaurantMenuAdapter = new RestaurantMenuAdapter(catList);
                rvMenu.setAdapter(restaurantMenuAdapter);

                smoothScroller.setTargetPosition(getPositionWithName("Sandwich"));
                mLayoutManager.startSmoothScroll(smoothScroller);

            } catch (Exception e) {
                e.printStackTrace();
            }

下面是我的代码;

  smoothScroller = new LinearSmoothScroller(RestaurantMenuActivity.this) {
        @Override
        protected int getVerticalSnapPreference() {
            return LinearSmoothScroller.SNAP_TO_ANY;
        }
        @Override
        public PointF computeScrollVectorForPosition(int targetPosition) {
            return null;
        }
    };

smoothScroller.setTargetPosition(catList.get(5).getId());
mLayoutManager.startSmoothScroll(smoothScroller);

以下是api响应;

   {
  "Status":"Success",
  "StatusCode":"200",
  "Message":"data fetch successfully.",
  "Data":{
  "RestaurantID":"1",
  "ProductCategory":[
     {
        "CategoryID":"1",
        "CategoryName":"Restaurant Offers",
        "No_of_Product":2
     },
     {
        "CategoryID":"2",
        "CategoryName":"Cold Drinks",
        "No_of_Product":4
     },
     {
        "CategoryID":"3",
        "CategoryName":"Pizza",
        "No_of_Product":2
     },
     {
        "CategoryID":"4",
        "CategoryName":"Burger",
        "No_of_Product":1
     },
     {
        "CategoryID":"5",
        "CategoryName":"Sandwich",
        "No_of_Product":2
     },
     {
        "CategoryID":"6",
        "CategoryName":"Chinese",
        "No_of_Product":1
     },
     {
        "CategoryID":"7",
        "CategoryName":"Maxican",
        "No_of_Product":1
     }
  ]
  }
  }

Answer 1

我通过以下方式完成我的工作；

拿LinearLayoutManager

LinearLayoutManager mLayoutManager = new LinearLayoutManager(RestaurantMenuActivity.this);
rvMenu.setLayoutManager(mLayoutManager);

并滚动到如下代码所示的位置；

   int scrollPosition = 0;
    for (int j = 0; j < pos; j++) {
        scrollPosition += menuItem.getData().getProductCategory().get(j).getProductDetails().size();
        scrollPosition++;
    }
    mLayoutManager.scrollToPosition(scrollPosition);
    final Handler handler = new Handler();
    final int finalScrollPosition = scrollPosition;
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            View rclItemView = rvMenu.getChildAt(0);
            mLayoutManager.scrollToPositionWithOffset(finalScrollPosition, rclItemView.getBaseline());
        }
    }, 100);