Question

我正在尝试在我的RecyclerView上实现Onclick。我尝试了许多方法，但是最终导致应用程序崩溃。我也想在单击任何cardView时出现一个对话框。

我使用fireBase作为后端，对此我很陌生。

这是我的适配器类：

public class BlogRecyclerAdapter extends RecyclerView.Adapter<BlogRecyclerAdapter.ViewHolder> {
    public List<BlogPost>blogList;
    public Context context;
    private FirebaseFirestore firebaseFirestore;

    private static final int SECOND_MILLIS = 1000;
    private static final int MINUTE_MILLIS = 60 * SECOND_MILLIS;
    private static final int HOUR_MILLIS = 60 * MINUTE_MILLIS;
    private static final int DAY_MILLIS = 24 * HOUR_MILLIS;
    String dateString;

    public  BlogRecyclerAdapter(List<BlogPost>blogList){
        this.blogList=blogList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull final ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.blog_list_item,parent,false);
        context=parent.getContext();
        firebaseFirestore=FirebaseFirestore.getInstance();
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull final ViewHolder holder, int position) {
        String descData=blogList.get(position).getDesc();
        holder.setDescText(descData);
        String imageUrl=blogList.get(position).getImage_url();
        holder.setBlogImage(imageUrl);
        final String userId=blogList.get(position).getUser_id();
        firebaseFirestore.collection("Users").document(userId).get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
            @Override
            public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                if(task.isSuccessful()){
                    String username=task.getResult().getString("Name");
                    holder.setUserData(username);
                }
                else{

                }
            }
        });

        long miliseconds=blogList.get(position).getTimestamp().getTime();
        long now = System.currentTimeMillis();

        final long diff = now - miliseconds;
        if (diff < MINUTE_MILLIS) {
             dateString= "just now";
        } else if (diff < 2 * MINUTE_MILLIS) {
             dateString= "a minute ago";
        } else if (diff < 50 * MINUTE_MILLIS) {
             dateString= diff / MINUTE_MILLIS + " minutes ago";
        } else if (diff < 90 * MINUTE_MILLIS) {
             dateString= "an hour ago";
        } else if (diff < 24 * HOUR_MILLIS) {
             dateString= diff / HOUR_MILLIS + " hours ago";
        } else if (diff < 48 * HOUR_MILLIS) {
             dateString= "yesterday";
        } else {
             dateString= diff / DAY_MILLIS + " days ago";
        }
        // String dateString= DateFormat.format("MM/dd/yyyy",new Date(miliseconds)).toString();
        holder.setTime(dateString);
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{
        private View mView;
        private TextView descView;
        private ImageView blogImageView;
        private TextView blogDate;
        private TextView blogUserName;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            mView=itemView;
        }

        public void setUserData(String name){
            blogUserName=mView.findViewById(R.id.blogUserName);
            blogUserName.setText(name);
        }

        public void setDescText(String descText){
            descView=mView.findViewById(R.id.blogDesc);
            descView.setText(descText);
        }

        public void setBlogImage(String downloaduri){
            blogImageView=mView.findViewById(R.id.blogImage);
            Glide.with(context).load(downloaduri).apply(RequestOptions.bitmapTransform(new BlurTransformation(30,3))).into(blogImageView);
        }

        public void setTime(String date){
            blogDate=mView.findViewById(R.id.blogDate);
            blogDate.setText(date);
        }
    }
}

我尝试了许多实现方法，但均未成功。

Answer 1

与ListView相比，将onClickListener添加到RecyclerView是一个痛苦的过程。但是有一种方法可以做到。

首先，将此类添加到适配器。

public static class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
private OnItemClickListener mListener;

public interface OnItemClickListener {
    public void onItemClick(View view, int position);

    public void onLongItemClick(View view, int position);
}

GestureDetector mGestureDetector;

public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
    mListener = listener;
    mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            if (child != null && mListener != null) {
                mListener.onLongItemClick(child, recyclerView.getChildAdapterPosition(child));
            }
        }
    });
}

@Override public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
    View childView = view.findChildViewUnder(e.getX(), e.getY());
    if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
        mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
        return true;
    }
    return false;
}

@Override public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) { }

@Override
public void onRequestDisallowInterceptTouchEvent (boolean disallowIntercept){}
}

第二，将此侦听器添加到您的活动/片段

recyclerView.addOnItemTouchListener(new BlogRecyclerAdapter.RecyclerItemClickListener(getActivity(), recyclerView ,new BlogRecyclerAdapter.RecyclerItemClickListener.OnItemClickListener() {
                @Override public void onItemClick(View view, int position) {

                    // Do something here...
                }

                @Override public void onLongItemClick(View view, int position) {

                }
            })
    );

Answer 2

首先，要将ClickListener应用于项（卡片视图），因为RecyclerView没有默认项，因此您需要执行以下操作：

使用所需的功能定义适配器内部的公共接口（例如：OnClick（））
在您的活动中实现该界面
修改适配器的构造函数，以便它接收该接口的实例（您的活动可以实现它的实现）并声明您声明的接口类型的成员变量侦听器
在初始化适配器ex时将您的活动作为参数传递。 adapter = BlogrecyclerAdapter（this） 5，使您的blog_list_item在xml中可点击 6.设置clickListener给你的项目rootviewholder.itemview.setOnClickListener（（View）-> listener.OnClick（））
1. 如果需要，可以将一些参数传递给OnClick

回收站视图Onclick打开对话框，卡视图中显示数据

2 个答案: