Question

我正在使用recyclerview和cardview来显示详细信息，但是当我从sqlite删除特定行时，它仍然在视图中我现在不应该在哪里编码来刷新删除后recyclerview以及删除视图后如果我尝试添加新的详细信息，即卡片未显示在视图中。

当我滚动它时，我试图实现radiobutton更改如何停止它。

我是Android和recyclerview的新用户，因此我不知道在哪里实施notifyDataSetChanged()或invalidate()等代码你也可以帮我解决上述问题。

MyAdapter类

  public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {


static   List<EmployeeDetails> dbList;
static  Context context;
MyAdapter(Context context, List<EmployeeDetails> dbList ){
    this.dbList = new ArrayList<EmployeeDetails>();
    this.context = context;
    this.dbList = dbList;


}


@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(
            R.layout.card_item, null);

    // create ViewHolder

    ViewHolder viewHolder = new ViewHolder(itemLayoutView);
    return viewHolder;


}

@Override
public void onBindViewHolder(MyAdapter.ViewHolder holder, int position) {

    holder.name.setText(dbList.get(position).getName1());
    holder.phone.setText(dbList.get(position).getPhone1());


}

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

public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    public TextView name,phone;
    public ImageView i,edit,delete;
   // public RadioButton p,a,l;


     DatabaseHelper helper=new DatabaseHelper(MyAdapter.context);


    public ViewHolder(View itemLayoutView) {
        super(itemLayoutView);


        i=(ImageView)itemLayoutView.findViewById(R.id.empimage);
        name = (TextView) itemLayoutView
                .findViewById(R.id.rvname);
        phone = (TextView)itemLayoutView.findViewById(R.id.rvphone);

        edit=(ImageView)itemLayoutView.findViewById(R.id.edit);
        delete=(ImageView)itemLayoutView.findViewById(R.id.delete);

       /* p=(RadioButton)itemLayoutView.findViewById(R.id.Present);
        a=(RadioButton)itemLayoutView.findViewById(R.id.Absent);
        l=(RadioButton)itemLayoutView.findViewById(R.id.Leave);
  */


        itemLayoutView.setOnClickListener(this);
        delete.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v)
                    {

                        String s=name.getText().toString();
                        EmployeeDetails e=new EmployeeDetails();

                        helper.deleteARow(s);



                    }
                }



        );


    }




    @Override
    public void onClick(View v) {

    }

实施Recyclerview的课程

 public class Employees extends Fragment implements View.OnClickListener {
DatabaseHelper helpher;
List<EmployeeDetails> dbList;
RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;


public Employees() {

}

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

    View rootView = inflater.inflate(R.layout.employees, container, false);

    FloatingActionButton fab= (FloatingActionButton) rootView.findViewById(R.id.fab);

    fab.setOnClickListener(this);




   //Recycle

    helpher=new DatabaseHelper(getActivity());

    dbList= new ArrayList<EmployeeDetails>();
    dbList = helpher.getDataFromDB();


    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.rv_recycler_view);
    mRecyclerView.setHasFixedSize(true);

    // use a linear layout manager
   mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);

    // specify an adapter
    mAdapter = new MyAdapter(getActivity(),dbList);
    mRecyclerView.setAdapter(mAdapter);
  //  mAdapter.notifyDataSetChanged();
   // mRecyclerView.invalidate();
    return rootView;

}



@Override
public void onClick(View view) {
    Intent intent=new Intent(getActivity(),addemployee.class);
    startActivity(intent);
}

帮助我，我在互联网上搜索了很多，但我找不到合适的方式

修改

我的db代码检索数据

           public List<EmployeeDetails> getDataFromDB(){
    List<EmployeeDetails> modelList = new ArrayList<EmployeeDetails>();
    String query = "select name,phone_no from "+TABLE_NAME1;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(query,null);

    if (cursor.moveToFirst()){
        do {
            EmployeeDetails model = new EmployeeDetails();
            model.setName1(cursor.getString(0));
            model.setPhone1(cursor.getString(1));
           // model.setRoll(cursor.getString(2));
            //model.setAddress(cursor.getString(3));
            //model.setBranch(cursor.getString(4));

            modelList.add(model);
        }while (cursor.moveToNext());
    }

Answer 1

看起来您想在点击删除图片后删除该行。

好的，请致电notifyItemRemoved(position); 在delete.setOnClickListene（.....）。

中

并确保您的删除操作从dbList实例中删除该条目，否则刷新后将显示已删除的行（当您重新运行活动或滚动时）

如果函数helper.deleteARow(s);刷新dbList，则在delete.setOnClickListene（.....）内的notifyItemRemoved(position);行之后调用helper.deleteARow(s);。

新代码：

 delete.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v)
                {

                    String s=name.getText().toString();
                    EmployeeDetails e=new EmployeeDetails();

                    helper.deleteARow(s);

                   notifyItemRemoved(position);`

                }
            }



    );

你也可以调用notifyDataSetChanged（），但它会刷新所有不必要的行。

Recycler View无法刷新卡片

1 个答案: