从RealmDatabase中检索数据并将其设置为GridView [英] Retrieve the Data From the RealmDatabase and Set it to GridView

问题描述

我可以将JSON数据保存到Realm数据库。我曾用作Realm的文档，但我无法将数据设置为GridView。我正在使用自定义适配器而不是Realm适配器。数据已记录，但不会显示给GridView。这是如何将数据检索并显示到GridView？

PopularDestinationGridDetail 这是JSON数据被解析并保存到数据库的位置

  Realm.init（this）; 
 realm = Realm.getDefaultInstance（）; 
 LinearAddTOFavourite.setOnClickListener（new View.OnClickListener（）{
 @Override 
 public void onClick（View v）{
 savetoDatabase（）; 
} 
 }）; 
 
 $ b $ public void savetoDatabase（）{
 
 realm.executeTransactionAsync（new Realm.Transaction（）{
 @Override 
 public void execute （Realm bgRealm）{
 RealmDatabasePopularDestination realmDatabasePopularDestination = bgRealm.createObject（RealmDatabasePopularDestination.class）; 
 realmDatabasePopularDestination.setTitle（title）; 
 realmDatabasePopularDestination.setTitle（latitude）; 
 realmDatabasePopularDestination.setTitle （longitude）; 
 realmDatabasePopularDestination.setImage（image）; 
 
 // Toast.makeText（this，realmDatabasePopularDestination.setLatitude（realmDatabasePopularDestination1.getLatitude（）））
 
 
 
}，new Realm.Transaction.OnSuccess（）{
 @Override 
 public void onSuccess（）{
 
 Log.v（Success ，title）; 
 
 
 $ b $，new Realm.Transaction.OnError（）{
 @Override 
 public void onError（Throwable error）{
 Log.e（failed ，error.getMessage（））; 
} 
}）; 
 
 
 
  

收藏夹

  public class Fragment {
 
 Realm realm; 
 GridView gridViewBookmark; 
 ArrayList< RealmDatabasePopularDestination> destination_bookmark_realm = new ArrayList<>（）; 
 
 @Nullable 
 @Override 
 public View onCreateView（LayoutInflater inflater，@Nullable ViewGroup容器，@Nullable Bundle savedInstanceState）{
 
 Realm.init的getContext（））; 
 realm = Realm.getDefaultInstance（）; 
 
 
 RealmDatabasePopularDestination realmDatabasePopularDestination = new RealmDatabasePopularDestination（）; 
 
 
查看视图= inflater.inflate（R.layout.bookmark_layout_gridview，container，false）; 
 gridViewBookmark =（GridView）view.findViewById（R.id.gridviewBookmark）; 
 destination_bookmark_realm.add（realmDatabasePopularDestination）; 
 getData（）; 
返回视图; 
 
 
 
 $ b public void getData（）{
 FavouriteAdapter favouriteAdapter = new FavouriteAdapter（getContext（），destination_bookmark_realm）; 
 gridViewBookmark.setAdapter（favouriteAdapter）; 
 
 RealmResults< RealmDatabasePopularDestination> result = realm.where（RealmDatabasePopularDestination.class）.equalTo（Title，niyash temple）。findAll（）; 
 
 result.load（）; 
 
 System.out.println（Result is+ result）; 
 
 // String output =; 
 // for（RealmDatabasePopularDestination realmDatabasePopularDestination：result）{
 // 
 // 
 //输出+ = realmDatabasePopularDestination.toString（）; 
 // 
 //} 
 // 
 // System.out.println（output+ output）; 
 // System.out.println（Total size =+ result.size（））; 
 
 
 
 $ b  

getter和setter

  public class RealmDatabasePopularDestination extends RealmObject {
 
 String Title; 
字符串纬度; 
字符串经度; 
 String image; 
 
 
 
 public String getTitle（）{
 return Title; 
} 
 
 public void setTitle（String title）{
 Title = title; 
} 
 
 public String getLatitude（）{
 return Latitude; 
} 
 
 public void setLatitude（String latitude）{
 Latitude = latitude; 
} 
 
 public String getLongitude（）{
 return Longitude; 
} 
 
 public void setLongitude（String longitude）{
 Longitude = longitude; 
} 
 
 public String getImage（）{
 return image; 
} 
 
 public void setImage（String image）{
 this.image = image; 
} 
} 
  

FavouriteAdapter

  public class FavouriteAdapter extends BaseAdapter {
 
 Context mContext; 
 ArrayList< RealmDatabasePopularDestination> clas_realm_bookmark = null; 
 String TAG =HomeTab_adapter; 
 
 $ b public FavouriteAdapter（上下文mContext，ArrayList< RealmDatabasePopularDestination> clas_realm_bookmark）{
 super（）; 
 this.mContext = mContext; 
 this.clas_realm_bookmark = clas_realm_bookmark; 
 
 
 $ b @覆盖
 public int getCount（）{
 
 return clas_realm_bookmark.size（）; 
} 
 
 @Override 
 public Object getItem（int position）{
 return clas_realm_bookmark.get（position）; 
} 
 
 @Override 
 public long getItemId（int position）{
 return position; 
} 
 
 @Override 
 public View getView（final int position，View convertView，ViewGroup parent）{
 final FavouriteAdapter.Holder viewHolder; 
 
 if（convertView == null）{
 //膨胀布局
 LayoutInflater inflater =（LayoutInflater）mContext.getSystemService（Context.LAYOUT_INFLATER_SERVICE）; 
 // LayoutInflater inflater = LayoutInflater.from（parent.getContext（））; 
 convertView = inflater.inflate（R.layout.bookmark_grid_list_item，parent，false）; 
 
 //设置好ViewHolder 
 // viewHolder = new ClassScheduleStudentAdapter.Holder（）; 
 viewHolder = new FavouriteAdapter.Holder（）; 
 
 // viewHolder.popular_destintion_id =（TextView）convertView.findViewById（R.id.student_profile_subject）; 
 viewHolder.title =（TextView）convertView.findViewById（R.id.festivalName）; 
 viewHolder.imageLogo =（ImageView）convertView.findViewById（R.id.event_festival_main_image）; 
 
 
 // Log.d（TAG，@@ postion：+ position +getTeacherName+ class_destination.get（position）.getId（））; 
 convertView.setTag（viewHolder）; 
 
 
} else {
 //我们避免每次在资源上调用findViewById（）
 //只使用viewHolder 
 // viewHolder =（ClassScheduleStudentAdapter.Holder）convertView.getTag（）; 
 viewHolder =（Holder）convertView.getTag（）; 
} 
 
 viewHolder.title.setText（clas_realm_bookmark.get（position）.getTitle（））; 
 
 
 Picasso.with（mContext）.load（clas_realm_bookmark.get（position）.getImage（））。error（R.drawable.close）.into（viewHolder.imageLogo）; 
 
 
返回convertView; 
} 
 
类持有者{
 TextView title; 
 ImageView imageLogo; 
 
} 
 
 
} 
  

我没有收到任何错误，但它们没有设置在ListView上。这是第一次使用领域，所以不要让我做错了。

解决方案

在从数据库提取数据之前，您正在将适配器设置为列表视图。

  RealmResults< RealmDatabasePopularDestination> ; result = realm.where（RealmDatabasePopularDestination.class）.equalTo（Title，niyash temple）。findAll（）; 
 result.load（）; 
 
 FavouriteAdapter favouriteAdapter = new FavouriteAdapter（getContext（），destination_bookmark_realm）; 
 gridViewBookmark.setAdapter（favouriteAdapter）; 
  

使用上面的代码和。

destination_bookmark_realm它应该加载你从databse获得的结果

I am able to Save the JSON Data to the Realm Database. I have used as the documentation of the Realm, but I am not able to set the data to the GridView. I am using Custom Adapter not the Realm Adapter. The Data are Logged but they are not Displayed to the GridView. How can this the Data be Retrieved and Displayed to the GridView?

PopularDestinationGridDetail this is where JSON data is parsed and saved to database

 Realm.init(this);
        realm = Realm.getDefaultInstance();
  LinearAddTOFavourite.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                savetoDatabase();
            }
        });


    public void savetoDatabase() {

        realm.executeTransactionAsync(new Realm.Transaction() {
            @Override
            public void execute(Realm bgRealm) {
                RealmDatabasePopularDestination realmDatabasePopularDestination = bgRealm.createObject(RealmDatabasePopularDestination.class);
                realmDatabasePopularDestination.setTitle(title);
                realmDatabasePopularDestination.setTitle(latitude);
                realmDatabasePopularDestination.setTitle(longitude);
                realmDatabasePopularDestination.setImage(image);

//                Toast.makeText(this,  realmDatabasePopularDestination.setLatitude(realmDatabasePopularDestination1.getLatitude()))


            }
        }, new Realm.Transaction.OnSuccess() {
            @Override
            public void onSuccess() {

                Log.v("Success",title);


            }
        }, new Realm.Transaction.OnError() {
            @Override
            public void onError(Throwable error) {
                Log.e("failed", error.getMessage());
            }
        });


    }

Favourites

public class Favourites extends Fragment {

    Realm realm;
    GridView gridViewBookmark;
    ArrayList<RealmDatabasePopularDestination> destination_bookmark_realm = new ArrayList<>();

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        Realm.init(getContext());
        realm = Realm.getDefaultInstance();


        RealmDatabasePopularDestination realmDatabasePopularDestination = new RealmDatabasePopularDestination();


        View view = inflater.inflate(R.layout.bookmark_layout_gridview, container, false);
        gridViewBookmark = (GridView) view.findViewById(R.id.gridviewBookmark);
        destination_bookmark_realm.add(realmDatabasePopularDestination);
        getData();
        return view;

    }


    public void getData() {
        FavouriteAdapter favouriteAdapter = new FavouriteAdapter(getContext(), destination_bookmark_realm);
        gridViewBookmark.setAdapter(favouriteAdapter);

        RealmResults<RealmDatabasePopularDestination> result = realm.where(RealmDatabasePopularDestination.class).equalTo("Title","niyash temple").findAll();

        result.load();

        System.out.println("Result is" + result);

//        String output = "";
//        for (RealmDatabasePopularDestination realmDatabasePopularDestination : result) {
//
//
//            output += realmDatabasePopularDestination.toString();
//
//        }
//
//        System.out.println("output" + output);
//        System.out.println("Total size=" + result.size());

    }

}

getter and setter

public class RealmDatabasePopularDestination extends RealmObject {

    String Title;
    String Latitude;
    String Longitude;
    String image;



    public String getTitle() {
        return Title;
    }

    public void setTitle(String title) {
        Title = title;
    }

    public String getLatitude() {
        return Latitude;
    }

    public void setLatitude(String latitude) {
        Latitude = latitude;
    }

    public String getLongitude() {
        return Longitude;
    }

    public void setLongitude(String longitude) {
        Longitude = longitude;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }
}

FavouriteAdapter

public class FavouriteAdapter extends BaseAdapter {

    Context mContext;
    ArrayList<RealmDatabasePopularDestination> clas_realm_bookmark = null;
    String TAG = "HomeTab_adapter";


    public FavouriteAdapter(Context mContext, ArrayList<RealmDatabasePopularDestination> clas_realm_bookmark) {
        super();
        this.mContext = mContext;
        this.clas_realm_bookmark = clas_realm_bookmark;
    }


    @Override
    public int getCount() {

        return clas_realm_bookmark.size();
    }

    @Override
    public Object getItem(int position) {
        return clas_realm_bookmark.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        final FavouriteAdapter.Holder viewHolder;

        if (convertView == null) {
            // inflate the layout
            LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            // LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            convertView = inflater.inflate(R.layout.bookmark_grid_list_item, parent, false);

            // well set up the ViewHolder
            //  viewHolder = new ClassScheduleStudentAdapter.Holder();
            viewHolder = new FavouriteAdapter.Holder();

            // viewHolder.popular_destintion_id = (TextView) convertView.findViewById(R.id.student_profile_subject);
            viewHolder.title = (TextView) convertView.findViewById(R.id.festivalName);
            viewHolder.imageLogo = (ImageView) convertView.findViewById(R.id.event_festival_main_image);


            //     Log.d(TAG, "@@ postion:" + position + " getTeacherName" + class_destination.get(position).getId());
            convertView.setTag(viewHolder);


        } else {
            // we've just avoided calling findViewById() on resource everytime
            // just use the viewHolder
            //  viewHolder = (ClassScheduleStudentAdapter.Holder) convertView.getTag();
            viewHolder = (Holder) convertView.getTag();
        }

        viewHolder.title.setText(clas_realm_bookmark.get(position).getTitle());


        Picasso.with(mContext).load(clas_realm_bookmark.get(position).getImage()).error(R.drawable.close).into(viewHolder.imageLogo);


        return convertView;
    }

    class Holder {
        TextView title;
        ImageView imageLogo;

    }


}

I am not getting any error but they are not set on the ListView.This is the first time using realm, so don't get where I am doing wrong.

解决方案

you are setting adapter to list view before extracting data from database.

RealmResults<RealmDatabasePopularDestination> result = realm.where(RealmDatabasePopularDestination.class).equalTo("Title","niyash temple").findAll();
result.load();

FavouriteAdapter favouriteAdapter = new FavouriteAdapter(getContext(), destination_bookmark_realm);
gridViewBookmark.setAdapter(favouriteAdapter);

use above code and.

destination_bookmark_realm it should be load with the result you got from databse

这篇关于从RealmDatabase中检索数据并将其设置为GridView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！