Question

我的问题与此类似。

Best approach to communicate between Fragment/Activity and RecyclerView.Adapter?

当用户单击“片段”中的按钮时，我知道如何在相应的活动中实现onClickListener，Interface和OnItemSelected方法。我有一个带有数组列表的片段。通过单击片段中数组列表中的每个项目，ExoPlayer将在新活动或片段中打开。据我了解，onItemClickListener不适用于Recyclerview。如何将onClick方法设置为列表中的项目？另外，我是否在RecyclerView之外设置onClick？这是我的RecyclerView适配器类。接口是否应该使用其他参数？先感谢您。

公共类StepsAdapter扩展了RecyclerView.Adapter {

private static final String TAG = StepsAdapter.class.getSimpleName();
private ArrayList<Steps> stepsList = new ArrayList<Steps>();
private StepsAdapter.StepsAdapterOnClickHandler mClickHandler;

/**
 * The interface that receives onClick messages.
 */
public interface StepsAdapterOnClickHandler {
    void onClick(Steps stepClick);
}

/**
 * Creates a StepsAdapter.
 *
 * @param clickHandler The on-click handler for this adapter. This single handler is called
 *                     when an item is clicked.
 */
public StepsAdapter(StepsAdapterOnClickHandler clickHandler,ArrayList<Steps> stepsList) {
    mClickHandler = clickHandler;
    this.stepsList = stepsList;
}

/**
 * Cache of the children views for a steps list item.
 */
public class StepsAdapterViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    @BindView(R.id.step_short_desc)
    public TextView stepShortDescription;

    @BindView(R.id.step_description)
    public TextView stepDescription;

    public StepsAdapterViewHolder(View view) {
        super(view);
        ButterKnife.bind(this, view);
        view.setOnClickListener(this);
    }

    /**
     * This gets called by the child views during a click.
     *
     * @param v The View that was clicked
     */
    @Override
    public void onClick(View v) {
        int adapterPosition = getAdapterPosition();
        Steps stepClick = stepsList.get(adapterPosition);
        mClickHandler.onClick(stepClick);
    }
}

@Override
public StepsAdapter.StepsAdapterViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
    Context context = viewGroup.getContext();
    int layoutIdForListItem = R.layout.steps_list_item;
    LayoutInflater inflater = LayoutInflater.from(context);
    boolean shouldAttachToParentImmediately = false;
    View view = inflater.inflate(layoutIdForListItem, viewGroup, shouldAttachToParentImmediately);
    return new StepsAdapter.StepsAdapterViewHolder(view);
}

@Override
public void onBindViewHolder(StepsAdapter.StepsAdapterViewHolder holder, int position) {

    //Binding data
    final Steps stepsView = stepsList.get(position);

    holder.stepShortDescription.setText(stepsView.getStepShortDescription());
    holder.stepDescription.setText(stepsView.getStepDescription());
}

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

public void setStepsList(ArrayList<Steps> mStepsList) {
    this.stepsList = mStepsList;
    notifyDataSetChanged();
}

}

相应的片段。点击方法是否正确实施？

public class StepsListFragment extends Fragment implements StepsAdapter.StepsAdapterOnClickListener {

    // Tag for logging
    private final String TAG = StepsListFragment.class.getSimpleName();

    @BindView(R.id.recyclerview_steps)
    RecyclerView mRecyclerView;

    ArrayList<Steps> stepsArrayList;

    Recipes recipes;

    // Final Strings to store state information about the list of steps and list index
    public static final String STEPS_LIST_INDEX = "list_index";


    // Define a new interface OnStepsClickListener that triggers a callback in the host activity
    OnStepClickListener mCallback;

    // OnStepsClickListener interface, calls a method in the host activity named onStepSelected
    public interface OnStepClickListener {
        void onClick(Steps stepClick);
    }

    // Override onAttach to make sure that the container activity has implemented the callback
    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

//        // This makes sure that the host activity has implemented the callback interface
//        // If not, it throws an exception
        try {
            mCallback = (OnStepClickListener) context;
        } catch (ClassCastException e) {
            throw new ClassCastException(context.toString()
                    + " must implement OnStepSelectedListener");
        }
    }

   /**
     * Mandatory empty constructor for the fragment manager to instantiate the fragment
     */
    public StepsListFragment() {
    }

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

//        //Inflate the Steps fragment layout
        View rootView = inflater.inflate(R.layout.fragment_steps, container, false);
//        // Bind the views
        ButterKnife.bind(this, rootView);

        Bundle bundle = this.getArguments();
        if (bundle != null) {
            recipes = getArguments().getParcelable("Recipes");

            stepsArrayList = new ArrayList<>();
            stepsArrayList = recipes.getRecipeSteps();
        }
        if (savedInstanceState != null) {
            //Restore the fragment's state here
            stepsArrayList = savedInstanceState.getParcelableArrayList(STEPS_LIST_INDEX);
        }

        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getContext());
        mRecyclerView.setLayoutManager(mLayoutManager);
        Log.i("listSteps", stepsArrayList.size() + "");

        StepsAdapter stepsAdapter = new StepsAdapter(this, stepsArrayList);
        mRecyclerView.setAdapter(stepsAdapter);

        // Return the root view
        return rootView;
}

public void onClick(Steps stepClick){
        mCallback.onClick(stepClick);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveIn`enter code here`stanceState(outState);

        //Save the fragment's state here
        outState.putParcelableArrayList(STEPS_LIST_INDEX, stepsArrayList);
        super.onSaveInstanceState(outState);
    }  }

Answer 1

在recyclerview Viewholder内部填充视图时，在recyclerview的每个项目上实现点击功能的最佳方法是初始化onClickListener。然后在onClick方法中，使用自定义界面/监听器来捕获父片段/活动中的点击活动。

例如：创建一个这样的自定义界面；

public interface RecyclerviewOnClickListener{
void recyclerviewClick(int position);
}

现在在包含recyclerview的父活动/片段中实现此接口。假设您的片段名称是ChatFragment。然后，

public class ChatFragment extends Fragment implements RecyclerviewOnClickListener{
.
.
}

这将在片段中实现onClick（int position）函数。在您的适配器构造函数中，您应该为RecyclerviewOnClickListener创建一个字段。假设您的适配器名称是ChatAdapter，然后

适配器构造器。

public ChatAdapter(RecyclerviewClickListener listener, .....<other params>){
this.listener = listener;
}

在片段中，您可以像下面那样初始化适配器

ChatAdapter adapter = new ChatAdapter(this, <any additional params>);

您还应该将相同的“侦听器”实例传递给您的观看者，并在那里也初始化监听器

现在，在您的recyclerview ViewHolder中，您可以设置view.setOnClickListener(new OnClickListener{ this.listener.recyclerviewClick(getAdapterPosition()) });

getAdapterPosition()函数返回单击在recyclerview中的位置，这将在片段的recyclerviewClick（）函数中获得回调。

关于您传递的参数数量，您可以根据需要使用任意数量，但是对于recyclerview中的click函数，理想的方法是仅使用该位置的一个参数。现在，您可以修改从片段传递到适配器的列表中的内容，并调用notifyDataSetChanged（）来更新recyclerview。希望一切都清楚。

Answer 2

在OnBindviewHolder中尝试

 holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
              //code here

        }

如何在片段中实现recyclerview onClick？

2 个答案: