RecyclerView 中的数据未从 Fragment 传递到适配器

Question

创建 a 后RecyclerView，我注意到我在 aBundle中声明的字符串没有从 传递Fragment到AlertDialog，并且连接的文本视图显示为空白。有谁知道出了什么问题？我是否需要为此场景或其他场景使用意图？在片段中使用：Bundle bundle = new Bundle();bundle.putString("goalreached",  getResources().getString(R.string.goal_reached));bundle.putString("day",  getResources().getString(R.string.today));bundle.putString("distance",  getResources().getString(R.string._3_2_km));bundle.putString("calories",  getResources().getString(R.string._213_kcal));用于适配器：Bundle bundle = new Bundle();String goalreached = bundle.getString("goalreached");   String day = bundle.getString("day");String distance = bundle.getString("distance");                        String calories = bundle.getString("calories");片段类public class TabFragmentRV extends android.support.v4.app.Fragment {    RecyclerView mRecyclerView;    public TabFragmentRV() {}    @Override    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {        return inflater.inflate(R.layout.fragment_rv, container, false);    }    @Override    public void onActivityCreated(@Nullable Bundle savedInstanceState) {        View v = getView();        assert v != null;        mRecyclerView = v.findViewById(R.id.my_recyclerview);        mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));        Bundle bundle = new Bundle();        bundle.putString("goalreached",  getResources().getString(R.string.goal_reached));        bundle.putString("day",  getResources().getString(R.string.today));        bundle.putString("distance",  getResources().getString(R.string._3_2_km));        bundle.putString("calories",  getResources().getString(R.string._213_kcal));        super.onActivityCreated(savedInstanceState);        initRVAdapter();     }}

Answer 1

您需要将第一个创建的包传递到您的适配器中（可能是在创建时）

这是具有必要更改的类

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

    private final static int TYPE_TABLE = 1, TYPE_SEPARATOR = 2;

    private ArrayList myArrayList = new ArrayList();

    private Context context;

    //Added Global bundle

    Private Bundle mBundle;

    public RVItemsAdapter(Context context){

        this. context=context;

    }

    //Added Constructor

    public RVItemsAdapter(Context context, Bundle bundle){

        this.context=context;

        this.mBundle = bundle;

    } 

    public void setCallSMSFeed(List<Object> myArrayList){

        this.myArrayList = (ArrayList) myArrayList;

    }

    @Override

    public int getItemViewType(int position) {

        if (myArrayList.get(position) instanceof TableRV) {

            return TYPE_TABLE;

        } else if (myArrayList.get(position) instanceof RVLineSeparator) {

            return TYPE_SEPARATOR;

        }

        throw new IllegalArgumentException("Item at position " + position + " is not an instance of either Phonecall or SMSmessage");

    }

    //Update Bundle

    public void updateView(Bundle bundle){

        mBundle = bundle;

        this.notifyDataSetChanged();

    }

    @Override

    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {

        int viewType=holder.getItemViewType();

        switch (viewType){

            case TYPE_TABLE:

                TableRV tblRV = (TableRV) myArrayList.get(position);

                ((TblViewHolder)holder).bind(tblRV);

                break;

            case TYPE_SEPARATOR:

                ((SeparatorViewHolder)holder).showSeparatorDetails();

                break;

            default:

                throw new IllegalArgumentException("unexpected viewType: " + viewType);

        }

    }

    @Override

    public int getItemCount(){return myArrayList.size();}

    @NonNull

    @Override

    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        int layout;

        RecyclerView.ViewHolder viewHolder;

        switch (viewType){

            case TYPE_TABLE:

                layout = R.layout.cardview_tableview_withexpandability;

                View tblView = LayoutInflater

                        .from(parent.getContext())

                        .inflate(layout, parent, false);

                viewHolder = new TblViewHolder(tblView);

                break;

            case TYPE_SEPARATOR:

                layout = R.layout.lineseparatorforrecyclerview;

                View separatorView = LayoutInflater

                        .from(parent.getContext())

                        .inflate(layout, parent, false);

                viewHolder = new SeparatorViewHolder(separatorView);

                break;

            default:

                throw new IllegalArgumentException("unexpected viewType: " + viewType);

        }

        return viewHolder;

    }

    public class TblViewHolder extends RecyclerView.ViewHolder {

        final Typeface iconFont = FontManager.getTypeface(context, FontManager.FONTAWESOME);

        private Button btnToday, btnYesterday, btnThisWeek, btnThisMonth;

        private TextView arrowexpandcollapseTextView, sectionNameTextView;

        TblViewHolder(View itemView) {

            super(itemView);

            btnMale.setOnClickListener(new View.OnClickListener() {

                @Override

                public void onClick(View v) {

                    AlertDialog alertDialog = new AlertDialog.Builder(v.getContext()).create();

                    alertDialog.setButton(Dialog.BUTTON_NEUTRAL,"OK",new DialogInterface.OnClickListener(){

                        @Override

                        public void onClick(DialogInterface dialog, int which) {

                            dialog.dismiss();

                        }

                    });

                    LayoutInflater inflater = LayoutInflater.from(context);

                    @SuppressLint("InflateParams") View content = inflater.inflate(R.layout.dialog_stats, null);

                    alertDialog.setView(content);

                    //Pulling String out of bundle

                    String goalreached = mBundle.getString("goalreached");   

                    String day = mBundle.getString("day");

                    String distance = mBundle.getString("distance");                        

                    String calories = mBundle.getString("calories");

                    ImageView imgdialogMain = content.findViewById(R.id.imgView_genderA);

                    ivGenderA.setImageResource(R.drawable.ic_male);

                    TextView tvGoalReached = content.findViewById(R.id.txtView_dialog_goalreached);

                    tvGoalReached.setText(goalreached);

                    TextView tvDay = content.findViewById(R.id.txtView_day);

                    tvDay.setText(day);

                    TextView tvImgviewWalking = content.findViewById(R.id.imgView_walking);

                    TextView tvDistance = content.findViewById(R.id.txtView_distance);

                    tvDistance.setText(distance);

                    TextView tvImgviewFire = content.findViewById(R.id.imgView_fire);

                    TextView tvCaloriesBurned = content.findViewById(R.id.txtView_location);

                    tvCaloriesBurned.setText(calories);

                    alertDialog.show();

                }

            });

        }

    }

}

目前，您只是在片段中创建一个新包并向其中添加字符串，然后什么也不做，然后在适配器中创建另一个新包并尝试拉出不存在的字符串。

要更新数据，您可以在需要更新数据时在要调用的适配器中尝试类似的操作（不过，我不确定 notifyDataSetChanged() 是否可以在适配器内部工作）：

//Update Bundle

public void updateView(Bundle bundle){

    mBundle = bundle;

    this.notifyDataSetChanged();

}

Answer 2

您正在尝试从这里的新捆绑包中获取额外内容：

Bundle bundle = new Bundle();

String goalreached = bundle.getString("goalreached");

...

您需要获取存储该信息的包。捆绑包只是信息的“容器”，因此您需要存储它然后检索它。

您永远不会将捆绑包保存在任何地方，因此您以后无法阅读。

我不确定你想在这里做什么，所以我不能给你一个例子，但看看这个：

Bundle bundle = new Bundle();

bundle.putString("goalreached",  getResources().getString(R.string.goal_reached));

bundle.putString("day",  getResources().getString(R.string.today));

bundle.putString("distance",  getResources().getString(R.string._3_2_km));

bundle.putString("calories",  getResources().getString(R.string._213_kcal));

您正在创建该捆绑包，然后存储信息，仅此而已。你永远不会把它存放在任何地方。

捆绑包的基本用法是将其存储在意图上，然后检索该意图并获取捆绑包。