Question

在我的应用中，我正在计算日期时差。在firebase中插入节点时，我节省了创建节点的当前时间。在适配器中，我希望以秒为单位或几天显示cardview的差异问题是适配器中没有编译时错误。但是textview中没有显示任何内容。

这是我在firebase中插入节点的活动

        addMovie.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            String currentDateTime = DateFormat.getDateTimeInstance().format(new Date());

            String title = etTitle.getText().toString();
            String desc = etDesc.getText().toString();
            String url = etUrl.getText().toString();
            String cst = etCast.getText().toString();
            savedData(title, desc, url,cst,currentDateTime);
}

    private void savedData(String title, String desc, String url,String cast,String time) {
    String key = updateId;
    if (updateId == null) {
        key = databaseReference.push().getKey();
    }

    uploadImage(selectedimg, key);
    Movie movie = new Movie(title, desc, url, key,cast,time);
    Toast.makeText(this, "movie "+movie.getCast(), Toast.LENGTH_SHORT).show();
    movieReference.child(key).setValue(movie);
    etTitle.setText("");
    etDesc.setText("");
    etUrl.setText("");
    movieImage.setImageResource(0);
    pd.dismiss();
}

这是我的适配器

public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {

ArrayList<Movie> movies;
movieItemListener listener;
Context context;
FirebaseDatabase firebaseDatabase;
DatabaseReference databaseReference;
DecimalFormat df;


public MyAdapter(ArrayList<Movie> movies) {
    this.movies = movies;
}

public MyAdapter(@NonNull Context context, ArrayList<Movie> movies, movieItemListener listener) {
    this.context = context;
    this.movies = movies;
    this.listener = listener;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_layout, parent, false);
    MyViewHolder viewHolder = new MyViewHolder(view);
    return viewHolder;
}

@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {


    df = new DecimalFormat("#.#");
    final Movie movie = movies.get(position);

    String currentTime = DateFormat.getDateTimeInstance().format(new Date());
    final String saveTime = movie.getCurrentDateTime();

    Toast.makeText(context, "abc"+getTimeDiff(currentTime, saveTime), Toast.LENGTH_SHORT).show();

    holder.tvDate.setText(getTimeDiff(currentTime, saveTime));

    holder.tvRatings.setText(df.format(movie.getAvgRating()));

    firebaseDatabase = FirebaseDatabase.getInstance();
    databaseReference = firebaseDatabase.getReference().child("movies");

    databaseReference.child(movie.getId()).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            holder.tvRatings.setText(df.format(dataSnapshot.child("avgRating").getValue()));
            holder.tvViews.setText(String.valueOf(dataSnapshot.child("viewsCount").getValue()) + " Views");
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

    holder.tvTitle.setText(movie.getTitle());

    holder.overflow.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            showPopupMenu(holder.overflow, position, movie);
        }
    });
}

private String getTimeDiff(String currentTime, String saveTime) {
    String diff="";
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/M/yyyy hh:mm:ss");

    try {
        Date date1 = simpleDateFormat.parse(currentTime);
        Date date2 = simpleDateFormat.parse(saveTime);

        diff= printDifference(date1, date2);
        Toast.makeText(context, "in diff ", Toast.LENGTH_SHORT).show();

    } catch (ParseException e) {
        e.printStackTrace();
    }
  return diff;
}


public String printDifference(Date startDate, Date endDate) {

    long different = endDate.getTime() - startDate.getTime();

    long secondsInMilli = 1000;
    long minutesInMilli = secondsInMilli * 60;
    long hoursInMilli = minutesInMilli * 60;
    long daysInMilli = hoursInMilli * 24;

    long elapsedDays = different / daysInMilli;
    different = different % daysInMilli;

    long elapsedHours = different / hoursInMilli;
    different = different % hoursInMilli;

    long elapsedMinutes = different / minutesInMilli;
    different = different % minutesInMilli;

    long elapsedSeconds = different / secondsInMilli;

    String days=String.valueOf(elapsedDays);
    String hours=String.valueOf(elapsedHours);
    String minutes=String.valueOf(elapsedMinutes);
    String seconds=String.valueOf(elapsedSeconds);

 /*  if(elapsedSeconds>59)
       return minutes;
    else if(elapsedMinutes>59)
        return hours;
    else if(elapsedHours>24)
        return days;
    else*/
        return seconds;
}


private void showPopupMenu(View view, final int position, final Movie movie) {
    PopupMenu popup = new PopupMenu(context, view);
    MenuInflater inflater = popup.getMenuInflater();
    inflater.inflate(R.menu.movie_menu, popup.getMenu());
    popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.action_edit:
                    listener.onUpdate(movie);
                    notifyDataSetChanged();
                    return true;
                case R.id.action_delete:
                    listener.onDelete(movie, position);
                    return true;
                default:
            }
            return false;
        }
    });
    popup.show();
}

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

我一直在寻找很长时间但未能找到解决办法有谁知道我在这做错了什么？

Answer 1

您使用的是错误的模式，这会导致异常并且diff将作为空标记返回，因此您可以使用

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss");

    try {
        Date date1 = simpleDateFormat.parse(currentTime);
        Date date2 = simpleDateFormat.parse(saveTime);

即使是更好的解决方案，也可以使用

DateFormat df = DateFormat.getDateTimeInstance();    
    try {
        Date date1 = df.parse(currentTime);
        Date date2 = df.parse(saveTime);

Answer 2

我完全不明白，但希望这可能有用在您的节点中，将当前日期保存为

long currentDateTime=new Date().getTime();

然后在你的getTimeDifference方法

private String getTimeDifference(){
   long difference=new Date().getTime()-movie.getCurrentDateTime();
   DateFormat formatter = new SimpleDateFormat("HH:mm:ss:SSS");
   return formatter.format(new Date(difference));
}

null日期时间差显示在textview中

2 个答案: