如何对回收器视图SQLite内容进行排序

Question

我有一个视图，其中显示了我的一堆Sqlite数据。我最近在数据库中添加了一个名为location_position的列。我在我的相对布局中添加了一个按钮，这样当它被点击时，我希望里面的数据以升序排列。我试着在网上举了几个例子，但按照我的应用程序的设置方式，我很难让它发挥作用。

我有一个routeView.java类和一个routeAdapter

如果有人能告诉我如何在点击按钮时对内容进行排序，或者任何具有类似解决方案的资源，我会非常感激

public class RouteView extends AppCompatActivity {
RecyclerView recyclerView;
routeAdapter routeAdapter;
ArrayList<String>  location_id, location_name, location_county, location_description, location_route, location_position;
MyDatabaseHelper myDB;
Button createPDFButton, btnNorth, southBtn;
Context mContext = this;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_route_view);
Button southBtn = findViewById(R.id.button_south);

southBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Collections.sort(ArrayList);
}
});
// btnRemove = findViewById(R.id.btnRemove);
recyclerView = findViewById(R.id.recyclerView);
myDB = new MyDatabaseHelper(this);
createPDFButton = findViewById(R.id.createPDFButton);
location_id = new ArrayList<>();
location_name =  new ArrayList<>();
location_county = new ArrayList<>();
location_description = new ArrayList<>();
location_route = new ArrayList<>();
location_position = new ArrayList<>();
Cursor cursor = myDB.readAllData();
createPDFButton.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
@Override
public void onClick(View v) {
if (UserActivity.checkAppPermission(RouteView.this, "android.permission.WRITE_EXTERNAL_STORAGE", 1)){
generatePDF(recyclerView);
}
}
});
while (cursor.moveToNext()){
if(cursor.getString(4).equals("1")) {
location_id.add(cursor.getString(0));
location_name.add(cursor.getString(1));
location_county.add(cursor.getString(2));
location_description.add(cursor.getString(3));
location_route.add(cursor.getString(4));
location_position.add(cursor.getString(8));
}
}
routeAdapter = new routeAdapter(this, this, location_id, location_name, location_county, location_description, location_route, location_position);
recyclerView.setAdapter(routeAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
}

这是路由适配器类

public class routeAdapter  extends RecyclerView.Adapter<routeAdapter.MyViewHolder> {
//private final ClickListener listener;
private Context context;
MyDatabaseHelper myDB;
Activity activity;
private ArrayList location_id, location_name, location_county, location_description, location_position, location_route, location_image_url;
Button btnRemove;
String id, name, county, description;
routeAdapter(Activity activity, Context context,  ArrayList location_id, ArrayList location_name, ArrayList location_county,
ArrayList location_description, ArrayList location_route, ArrayList location_position){
this.activity = activity;
this.context = context;
this.location_id = location_id;
this.location_name = location_name;
this.location_county = location_county;
this.location_description = location_description;
this.location_position = location_position;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.route_row, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, final int position) {
holder.location_id_txt.setText(String.valueOf(location_id.get(position)));
holder.location_name_txt.setText(String.valueOf(location_name.get(position)));
holder.location_county_txt.setText(String.valueOf(location_county.get(position)));
holder.location_description_txt.setText(String.valueOf(location_description.get(position)));

holder.mainLayout2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context, RouteView.class);
intent.putExtra("id", String.valueOf(location_id.get(position)));
intent.putExtra("name", String.valueOf(location_name.get(position)));
intent.putExtra("county", String.valueOf(location_county.get(position)));
intent.putExtra("description",String.valueOf(location_description.get(position)));
activity.startActivityForResult(intent, 2);
}
});
}
@Override
public int getItemCount()  { return location_id.size(); }
class MyViewHolder extends RecyclerView.ViewHolder {
TextView location_id_txt, location_name_txt, location_county_txt, location_description_txt, added_to_route_txt, location_image_url;
LinearLayout mainLayout2;
Button btnRemove;
public MyViewHolder(@NonNull View itemView) {
super(itemView);
location_id_txt = itemView.findViewById(R.id.location_id_txt);
location_name_txt = itemView.findViewById(R.id.location_name_txt);
location_county_txt = itemView.findViewById(R.id.location_county_txt); 
location_description_txt = itemView.findViewById(R.id.location_description_txt);
mainLayout2 = itemView.findViewById(R.id.mainLayout2);
}
}
}

Answer 1

这是基本概念：

单击某个按钮或其他按钮以特定顺序对事物进行排序时，您可以对ArrayList进行排序，该ArrayList包含RecyclerView中反映的值。然后更新/重新创建RecyclerView以注册更改。