android - 如何根据那里的位置在 RecyclerView 中隐藏/显示 imageview

Question

我的 RecyclerView 中有一个锁定图像，我想在长按时隐藏/显示它。.我想根据它的位置隐藏/显示，就像我在回收站 View 中长按第一个项目并单击隐藏它只会隐藏该项目的图像而不是其他项目我已经尝试过这个我面临的问题仅隐藏/显示最后一个位置项目中的图像。请帮助我在此先感谢。

回收 View 适配器

 public class RecycleViewAdapter extends 
 RecyclerView.Adapter<RecycleViewHolder> {
 private List<FileName> fileNames;
 private Context context;
 private OnItemClicked onClick;
 String Name;
 RecycleViewHolder mainHolder;

public RecycleViewAdapter(Context context,List<FileName> fileNames) {
    this.context = context;
    this.fileNames = fileNames;
 }
public interface OnItemClicked {
    void onItemClick(int position);
}

@Override
public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 
 {
    LayoutInflater mInflater = LayoutInflater.from(parent.getContext());
    ViewGroup mainGroup = (ViewGroup) mInflater.inflate(R.layout.grid_item, 
    parent, false);
    RecycleViewHolder listHolder = new RecycleViewHolder(mainGroup);
    return listHolder;

  }

@Override
public void onBindViewHolder(RecycleViewHolder holder, final int position) {
    final FileName model = fileNames.get(position);
    mainHolder = (RecycleViewHolder) holder;
    mainHolder.title.setText(model.getShorttext());
    mainHolder.note.setText(model.getName());
    mainHolder.cardView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onClick.onItemClick(position);

        }
    });
    mainHolder.setLongClickListener(new LongClickListener() {
        @Override
        public void onItemLongClick(int position) {

        }
    });
}

@Override
public int getItemCount() {
    return (null != fileNames ? fileNames.size() : 0);
}
public void setOnClick(OnItemClicked onClick)
{
    this.onClick=onClick;
}
public void getItemSelected(MenuItem item)
{
        if (item.getItemId() == 0) {
            mainHolder.imageView.setVisibility(View.VISIBLE);
        } else {
            mainHolder.imageView.setVisibility(View.INVISIBLE);
        }

}

RecyclerViewHolder:

 public class RecycleViewHolder extends RecyclerView.ViewHolder implements 
 View.OnLongClickListener,View.OnCreateContextMenuListener {
 public TextView title;
 public TextView note;
 public CardView cardView;
 public ImageView imageView;
 LongClickListener longClickListener;

 public RecycleViewHolder(View view) {
    super(view);
    this.title = (TextView) view.findViewById(R.id.title);
    this.note = (TextView) view.findViewById(R.id.note);
    this.cardView = (CardView) view.findViewById(R.id.card_view);
    this.imageView = (ImageView) view.findViewById(R.id.lock);
    imageView.setVisibility(View.INVISIBLE);
    view.setOnLongClickListener(this);
    view.setOnCreateContextMenuListener(this);


}
public void setLongClickListener(LongClickListener lc)
{
    this.longClickListener = lc;

}

@Override
public boolean onLongClick(View v) {
    this.longClickListener.onItemLongClick(getLayoutPosition());
    return false;
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, 
 ContextMenu.ContextMenuInfo menuInfo) {
    menu.add(0,0,0,"Lock");
    menu.add(0,1,0,"UnLock");

}
}

我从谷歌上找到这个来检查 Bindview 上的位置，但我不知道如何在 getItem selected 中实现

if (position == eventsList.size() -1){
holder.profileImage.setVisibility(View.INVISIBLE)
}else{
holder.profileImage.setVisibility(View.VISIBLE)
}

主要 Activity :

  public class MainActivity extends AppCompatActivity implements 
 RecycleViewAdapter.OnItemClicked{
List<FileName> filenames;
DBhelper dBhelper;
SQLiteDatabase sqLiteDatabase;
ListViewAdapter listViewAdapter;
ListView listView;
ImageView lock;
String name,note;
String col;
private static RecyclerView recyclerView;
RecycleViewAdapter recycleViewAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    checkFirstRun();
    //listView = (ListView)findViewById(R.id.lv_filename);
    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    lock =(ImageView)findViewById(R.id.lock);
    dBhelper = new DBhelper(getApplicationContext());
    sqLiteDatabase =dBhelper.getReadableDatabase();
    filenames = dBhelper.getItemFromDatabase(sqLiteDatabase);
    initViews();
    if(filenames != null) {
        recycleViewAdapter = new 
       RecycleViewAdapter(MainActivity.this,filenames);
        recyclerView.setAdapter(recycleViewAdapter);
        //listViewAdapter = new ListViewAdapter(getApplicationContext(), 
        R.layout.activity_main, filenames);
        //listView.setAdapter(listViewAdapter);
    }
        recycleViewAdapter.setOnClick(this);

      //        registerForContextMenu(listView);
   /* listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            name = filenames.get(position).getName();
            note = filenames.get(position).getShorttext();
            Alert();

        }
    });*/
}
private void initViews() {
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    recyclerView.setHasFixedSize(true);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setLayoutManager(new StaggeredGridLayoutManager(2, 
    StaggeredGridLayoutManager.VERTICAL));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_menu, menu);
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.action_add:
            Intent intent = new Intent(MainActivity.this, Note.class);
            startActivity(intent);
            return true;
        case R.id.action_pass:
            Intent i = new Intent(MainActivity.this, ChangePass.class);
            startActivity(i);
            return true;
        case R.id.action_list:
            Intent intent2 = new Intent(MainActivity.this, ToDo.class);
            startActivity(intent2);
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

public void Alert()
{
    View mview = getLayoutInflater().inflate(R.layout.dialog_pass,null);
    final EditText mEdittext = (EditText) mview.findViewById(R.id.Epass);
    AlertDialog.Builder mBuilder = new AlertDialog.Builder(MainActivity.this);
    mBuilder.setView(mview);
    mBuilder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {


        }
    });
    mBuilder.setNegativeButton("Cancel",null);
    mBuilder.setCancelable(false);
    final AlertDialog dialog = mBuilder.create();
    dialog.show();
    dialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            String col = mEdittext.getText().toString();
            String password = dBhelper.searchpass(col);
            if (col.equals(""))
            {
                mEdittext.setError("Please fill the blank field");
            }
            else if (col.equals(password))
            {
                Intent intent =  new Intent(MainActivity.this,Note2.class);
                intent.putExtra("Name",name);
                intent.putExtra("Note",note);
                startActivity(intent);
                dialog.dismiss();
            }
            else {
                Toast temp = Toast.makeText(MainActivity.this, "Password does not match", Toast.LENGTH_SHORT);
                temp.show();
            }
        }
    });

}
public void checkFirstRun() {
    boolean isFirstRun = getSharedPreferences("PREFERENCE", MODE_PRIVATE).getBoolean("isFirstRun", true);
    if (isFirstRun){

        View view = getLayoutInflater().inflate(R.layout.first_run_dialog,null);
        final EditText FirstPass = (EditText) view.findViewById(R.id.Fpass);
        final Button submit = (Button)view.findViewById(R.id.ok);
        final AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setCancelable(false);
        builder.setView(view);
        final AlertDialog dialog1 = builder.create();
        submit.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              col = FirstPass.getText().toString();
              if (col.equals(""))
              {
                  FirstPass.setError("Please fill the field");
              }
              else{
              savePass();
              Toast.makeText(MainActivity.this, "Password Created", Toast.LENGTH_SHORT).show();
                  dialog1.dismiss();
              }
          }
      });
        dialog1.show();
        dialog1.setCanceledOnTouchOutside(false);



        getSharedPreferences("PREFERENCE", MODE_PRIVATE)
                .edit()
                .putBoolean("isFirstRun", false)
                .apply();
    }
}
public void savePass()
{
    dBhelper = new DBhelper(this);
    sqLiteDatabase= dBhelper.getWritableDatabase();
    dBhelper.storePass(col,sqLiteDatabase);
}
@Override
public void onItemClick(int position) {
    name = filenames.get(position).getName();
    note = filenames.get(position).getShorttext();
    Alert();
}


@Override
public boolean onContextItemSelected(MenuItem item) {
    recycleViewAdapter.getItemSelected(item);
    return super.onContextItemSelected(item);
    }


 }   

我的界面:

public interface LongClickListener {
void onItemLongClick(int position);
 }

Answer 1

您需要跟踪适配器中锁定或解锁项目的位置，例如

ArrayList<Integer> lockedItems = new ArrayList<Interger>;

和向其中添加、删除项目。

或者您可以使用 Boolean你模型中的字段 FileName

实际上，您需要一种方法来识别给定位置的图像是否需要隐藏或显示

如果您知道是否需要在给定位置隐藏/显示，则可以在 onBindViewHolder 中更新 View 喜欢

    @Override
    public void onBindViewHolder(RecycleViewHolder holder, final int position) {
        final FileName model = fileNames.get(position);
        RecycleViewHolder recycleViewHolder = (RecycleViewHolder) holder;
        recycleViewHolder.title.setText(model.getShorttext());
        recycleViewHolder.note.setText(model.getName());
        if (model.isLocked()) { // or if (lockedItems.contains(position))
            recycleViewHolder.imageView.setVisibility(View.VISIBLE);
        } else {
            recycleViewHolder.imageView.setVisibility(View.INVISIBLE);
        }

已编辑

添加字段 selectedItem到适配器以跟踪长按的项目位置并在长按时存储项目位置

holder.setLongClickListener(new LongClickListener() {
    @Override
    public void onItemLongClick(int position) {
        selectedItem = position
    }
});

并在 getItemSelected 中使用该位置并将其添加到 lockedItemsList或添加 boolean FileName 中的字段并更新其值并使用它来了解给定位置的项目是锁定还是解锁。