Question

我有一个recyclerview和一个listview。 recyclerview的方向是水平的，固定在textview之后的屏幕顶部。 listview内部有另一个recyclerview。因此，当我单击最固定的recyclerview中的一项时，我想移动到listview的相同位置（可能正在使用smoothScrollToPosition）。我在网上搜索了所有内容，但找不到任何解决方案。有人可以帮我吗？预先感谢您的努力。

    @Override
    protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_category);

    Intent mIntent = getIntent();
    String title = mIntent.getStringExtra("title");
    mRetailer = mIntent.getStringExtra("retailer");
    setTitle(title.toUpperCase());
    headingTxt = (TextView) findViewById(R.id.txt_heading); //heading text
    subHeadingTxt = (TextView) findViewById(R.id.txt_sub_heading); //number of categories text
    }
    mCategories = new ArrayList<>();
    mCategories.clear();
    HorizontalScrollView hr = (HorizontalScrollView) findViewById(R.id.horizontal_scroll_categories);
    hr.setScrollBarSize(10);
    mRecyclerView = (RecyclerView) findViewById(R.id.categories_recyclerview);
    mRecyclerView.setScrollBarSize(10);

    //====== For category Lists ========

    categoryAdapter = new CategoryListViewAdapter(mRetailer);
    mListView = (ListView)findViewById(R.id.category_detail_listview);
    mListView.setDivider(null);
    mListView.setDividerHeight(0);
    mListView.setAdapter(categoryAdapter);

    OkHttpClient client = new OkHttpClient();
    String url = "http://serveraddress/MerchApp/web/get_all_category.php";
    final Request request = new Request.Builder()
            .url(url)
            .build();
    client.newCall(request).enqueue(new Callback() {
        String cateName, catePName;
        int cateId, cateUid, cateDepth;
        @Override
        public void onFailure(Call call, IOException e) {
            e.printStackTrace();
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            if(response.isSuccessful()){
                final String mResponse = response.body().string();
                CategoryActivity.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {


                        JSONArray jsonArray = null;
                        try {
                            JSONObject jsonObject = new JSONObject(mResponse);
                            jsonArray = jsonObject.getJSONArray("categories");  //JSONArray(mResponse);
                            JSONObject ob;
                            for(int i = 0; i<jsonArray.length(); i++){
                                ob = jsonArray.getJSONObject(i);

                                cateId=ob.getInt("cate_id");
                                cateName=ob.getString("cate_name");
                                cateUid=ob.getInt("cate_pid");
                                cateDepth=ob.getInt("cate_depth");

                                if(cateDepth == 0) {
                                    mCategories.add(new Categories(cateId, cateName, R.drawable.ic_music_note_black_35dp));
                                    CategoryInfo cateInfo=new CategoryInfo(cateId, cateName, "",CategoryActivity.this);
                                    categoryAdapter.addItem(cateInfo);
                                    categoryAdapter.notifyDataSetChanged();
                                }

                            }

                            // set 2depth(sub) category
                            for (int i = 0; i < jsonArray.length(); i++) { //
                                JSONObject subCateOb =jsonArray.getJSONObject(i);

                                cateId=subCateOb.getInt("cate_id");
                                cateName=subCateOb.getString("cate_name");
                                cateUid=subCateOb.getInt("cate_pid");
                                cateDepth=subCateOb.getInt("cate_depth");
                                catePName=subCateOb.getString("cate_pname");

                                if(cateDepth != 0) {
                                    SubcategoryInfo subCateInfo=new SubcategoryInfo(cateId, cateUid, cateName, catePName,"");
                                    categoryAdapter.categoryMap.get(cateUid).getSubCateAdapter().addSubCateItem(subCateInfo);
                                    categoryAdapter.categoryMap.get(cateUid).getSubCateAdapter().notifyDataSetChanged();
                                }

                            }
                            setHeader(); // set the top header categories

                        } catch (Exception e) {
                            e.printStackTrace();
                            LOGGER.info("!# Request error!!!!! : {}", e.getMessage());
                            //return "serverError";
                        }
                    }
                });
                setCategory(); //set the lower categories
            }
        }
    });
}
public void setHeader(){
    mAdapter = new CategoriesRecyclerViewAdapter(CategoryActivity.this, mCategories);
    mRecyclerView.setLayoutManager(new GridLayoutManager(CategoryActivity.this, mCategories.size()));
    mRecyclerView.setAdapter(mAdapter);
    subHeadingTxt.setText(mAdapter.getItemCount()+" Categories");
}
public void setCategory(){
    categoryAdapter = new CategoryListViewAdapter(mRetailer);
    mListView.setAdapter(categoryAdapter);

}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.retailers_search_menu, menu);
    MenuItem item = menu.findItem(R.id.search_retailers);
    final SearchView searchView = (SearchView) item.getActionView();
    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String s) {
            categoryAdapter.getFilter().filter(s);
            System.out.println("Submit Executed" + s);

            return false;
        }

        @Override
        public boolean onQueryTextChange(String s) {
            System.out.println("Changed Executed" + s);
            categoryAdapter.getFilter().filter(s);
            return false;
        }
    });
    return super.onCreateOptionsMenu(menu);
  }
}

和自定义RecyclerView适配器如下所示：

public class CategoriesRecyclerViewAdapter extends 
RecyclerView.Adapter<CategoriesRecyclerViewAdapter.MyViewHolder> 
implements Filterable {
private Context context;
private ArrayList<Categories> mCategories;
private ArrayList<Categories> mFilteredCategories;

public CategoriesRecyclerViewAdapter(Context context, 
ArrayList<Categories> mCategory) {
    mCategories = mCategory;
    mFilteredCategories = mCategory;
    this.context = context;
}

@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int i) {
    View view;
    LayoutInflater mInflater = LayoutInflater.from(context);
    view = mInflater.inflate(R.layout.category_header_thumbnail, parent, false);
    return new MyViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int position) {
    myViewHolder.mCategoryThumbnail.setImageResource(mCategories.get(position).getCategoryThumbnail());

}


@Override
public int getItemCount() {
        return mCategories.size();
}

public class MyViewHolder extends RecyclerView.ViewHolder{
    ImageView mCategoryThumbnail;
    CardView mCategoryCardView;
    public MyViewHolder(View itemView) {
        super(itemView);
        mCategoryThumbnail = (ImageView) itemView.findViewById(R.id.categories_img);
        mCategoryCardView = (CardView) itemView.findViewById(R.id.categories_card);
    }
}
@Override
public Filter getFilter() {
    return new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence charSequence) { charSequence.length());
            FilterResults results = new FilterResults();
            // if there is nothing to filter on, return the original List of Retailers;
            if(charSequence == null || charSequence.length() == 0){
                results.values = mFilteredCategories;
                results.count = mFilteredCategories.size();
            }else {
                List<Categories> filteredResultsData = new ArrayList<Categories>();
                for(Categories retailer: mFilteredCategories){
                    if(retailer.getCategoryName().toUpperCase().startsWith(charSequence.toString().toUpperCase())){
                        filteredResultsData.add(retailer);
                    }
                }
                results.values = filteredResultsData;
                results.count = filteredResultsData.size();
            }
            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            mCategories = (ArrayList<Categories>) results.values;

            notifyDataSetChanged();
        }
    };
  }
}

Answer 1

在您的课程中实现onItemClickListener。在这种实现的方法中，您将获得recyclerview项目的位置。

示例

  Class example implements CategoriesRecyclerViewAdapter.OnItemClickListener{
    Listview listView;//your listview
    ArrayList alListview;//arraylist for your listview
    @Override
    public void onItemclick(int position){
            if(alListview.size()>=position)
            listView.smoothScrollToPosition(position);
        }
}

您的适配器类

public class CategoriesRecyclerViewAdapter extends
        RecyclerView.Adapter<CategoriesRecyclerViewAdapter.MyViewHolder>
        implements Filterable {
    private Context context;
    private ArrayList<Categories> mCategories;
    private ArrayList<Categories> mFilteredCategories;
    private PetrolManFilterAdapter.OnItemClickListener listener;

    public CategoriesRecyclerViewAdapter(Context context,
                                         ArrayList<Categories> mCategory, PetrolManFilterAdapter.OnItemClickListener clickListener) {
        mCategories = mCategory;
        mFilteredCategories = mCategory;
        this.context = context;
        listener = clickListener;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int i) {
        View view;
        LayoutInflater mInflater = LayoutInflater.from(context);
        view = mInflater.inflate(R.layout.category_header_thumbnail, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int position) {
        myViewHolder.mCategoryThumbnail.setImageResource(mCategories.get(position).getCategoryThumbnail());
     myViewHolder.mCategoryThumbnail.setOnClickListener(v -> {
            listener.onItemclick(position);
        });
    }
    public Categories getItemAtPosition(int position) {
        return arrayList.get(position);
    }

    @Override
    public int getItemCount() {
        return mCategories.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder{
        ImageView mCategoryThumbnail;
        CardView mCategoryCardView;
        public MyViewHolder(View itemView) {
            super(itemView);
            mCategoryThumbnail = (ImageView) itemView.findViewById(R.id.categories_img);
            mCategoryCardView = (CardView) itemView.findViewById(R.id.categories_card);
        }
    }
    @Override
    public Filter getFilter() {
        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence charSequence) { charSequence.length());
                FilterResults results = new FilterResults();
                // if there is nothing to filter on, return the original List of Retailers;
                if(charSequence == null || charSequence.length() == 0){
                    results.values = mFilteredCategories;
                    results.count = mFilteredCategories.size();
                }else {
                    List<Categories> filteredResultsData = new ArrayList<Categories>();
                    for(Categories retailer: mFilteredCategories){
                        if(retailer.getCategoryName().toUpperCase().startsWith(charSequence.toString().toUpperCase())){
                            filteredResultsData.add(retailer);
                        }
                    }
                    results.values = filteredResultsData;
                    results.count = filteredResultsData.size();
                }
                return results;
            }

            @Override
            protected void publishResults(CharSequence constraint, FilterResults results) {
                mCategories = (ArrayList<Categories>) results.values;

                notifyDataSetChanged();
            }
        };
    }

    public interface OnItemClickListener {
        void onItemclick(int position);
    }
}

Answer 2

非常感谢您的参与，但我自己找到了解决方案。如果外面有人遇到相同或相似的问题，这就是我的做法。首先，我创建了一个名为 OnRecyclerViewItemClickListener 的recyclerview项目点击侦听器界面，如下所示

import android.view.View;
public interface OnRecyclerViewItemClickListener {
   void onItemClick(int position, View view);
}

使用此接口，我们可以在 Activity 或 Fragment 中实现它。这将覆盖我的活动中的itemclick方法。

然后，将以下内容添加到我的CategoriesRecyclerViewAdapter中。

....
private OnRecyclerViewItemClickListener onRecyclerViewItemClickListener;
public void setOnRecyclerViewItemClickListener(OnRecyclerViewItemClickListener onRecyclerViewItemClickListener) {
    this.onRecyclerViewItemClickListener = onRecyclerViewItemClickListener;
}
...

接下来，在onBindViewHolder方法中，我以这种方式声明了布局setOnclicklistener。

...
myViewHolder.mCategoryThumbnail.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (onRecyclerViewItemClickListener != null) {
                onRecyclerViewItemClickListener.onItemClick(position, v);
            }
        }
    });
 ...

要获取RecyclerView单击项目的位置，我将标签设置为CategoryActivity类中的layout，如下所示：

...
@Override
public void onItemClick(int position, View v) {
    Categories categories = (Categories) mListView.getTag();
    switch (v.getId()){
        case R.id.categories_img:
            mListView.smoothScrollToPosition(position);
            break;
    }

}
...

最后，我将我的onRecyclerViewItemClickListener设置为CategoryActivity类中的适配器，该类实际上是在我的类的setHeader方法中找到的，如下所示。（第5行是添加的代码）

1 ...
2 public void setHeader(){
3    mAdapter = new CategoriesRecyclerViewAdapter(CategoryActivity.this, mCategories);
4    mRecyclerView.setLayoutManager(new GridLayoutManager(CategoryActivity.this, mCategories.size()));
5    mAdapter.setOnRecyclerViewItemClickListener(this);
6    mRecyclerView.setAdapter(mAdapter);
7    subHeadingTxt.setText(mAdapter.getItemCount()+" Categories");
8 }
9 ...

仅此而已。对我来说效果很好。我希望它也对您有用，并节省您的时间。

干杯。~~

已更新：- 我忘了提到这一重要说明了。...不要忘记实现OnRecyclerViewItemClickListener接口。

 public class CategoryActivity extends AppCompatActivity implements OnRecyclerViewItemClickListener {...}

在项目上，单击RecyclerView的侦听器-如何使用项目在回收器视图中的位置来平滑滚动到另一个列表视图？

2 个答案: