我RecyclerView内的Fragment内Activity。我需要从RecyclerView刷新Activity。我在Fragment内添加了一个名为notifyDatasetChanged的方法来刷新RecyclerView。但是notifyDatasetChanged没有用。
这是我的Fragment。
public class CategoryFragment extends Fragment{
private RecyclerView recyclerView;
private EventsAdapter adapter;
static Context context = null;
private List<Category> categories;
private List<Item> allItems = new ArrayList();
private ReminderDatabase dbHandler;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(!checkDatabase()){
copyDatabase();
}
context = getActivity();
dbHandler = new ReminderDatabase(context);
fillAllItems();
}
public void fillAllItems(){
categories = dbHandler.getAllCategory();
for(int i=0;i<categories.size();i++){
Category category = categories.get(i);
Item categoryItem = new Item(category.getTitle(),category.getColor(),Category.CATEGORY_TYPE);
allItems.add(categoryItem);
List<Event> events = dbHandler.getEventsByCategory(category.getTitle());
for(int j=0;j<events.size();j++){
Event e = events.get(j);
Item eventItem = new Item(e.getId(),e.getTitle(),e.getDescription(),e.getPlace(),e.getCategory(),e.getTime(),e.getDate(),categoryItem.getColor(),e.isShow(),Event.EVENT_TYPE);
allItems.add(eventItem);
}
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.category_fragment, container, false);
recyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
adapter = new EventsAdapter(getContext(),allItems);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
return v;
}
public boolean checkDatabase(){
String path = "/data/data/com.example.materialdesign.reminder/databases/";
String filename = "Remind";
File file = new File(path+filename);
Log.d("Database","File exists -> "+file.exists());
return file.exists();
}
public void copyDatabase(){
String path = "/data/data/com.example.materialdesign.reminder/databases/Remind";
ReminderDatabase dbHandler = new ReminderDatabase(getContext());
dbHandler.getWritableDatabase();
InputStream fin;
OutputStream fout;
byte[] bytes = new byte[1024];
try {
fin = getActivity().getAssets().open("Remind");
fout = new FileOutputStream(path);
int length=0;
while((length = fin.read(bytes))>0){
fout.write(bytes,0,length);
}
fout.flush();
fout.close();
fin.close();
Log.d("Database","successfully copied database");
} catch (FileNotFoundException e) {
e.printStackTrace();
Log.d("Database","-Error" +e.getMessage());
} catch (IOException e) {
e.printStackTrace();
Log.d("Database","-Error" +e.getMessage());
}
}
@Override
public void onResume() {
super.onResume();
allItems.clear();
Log.d("TAG","onresume");
fillAllItems();
adapter.notifyDataSetChanged();
}
public void refresh(){
Log.d("c",allItems.size()+"");
allItems.clear();
fillAllItems();
Log.d("c",allItems.size()+"");
adapter.notifyDataSetChanged();
}
}
我从MainActivity调用了刷新方法。
@Override
public void onInserted() {
fragment.refresh();
}
我的Adapter就在这里。
public class EventsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
private Context context;
private List<Item> allItems = new ArrayList();
private HideOrShowListener hideOrShowListener;
public static final int EVENT_TYPE = 1;
public static final int CATEGORY_TYPE = 0;
private int lastPosition;
private boolean flag = false;
public EventsAdapter(Context context,List<Item> allItems){
this.context = context;
hideOrShowListener =(HideOrShowListener) context;
this.allItems = allItems;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
switch (viewType){
case CATEGORY_TYPE:
view = LayoutInflater.from(context).inflate(R.layout.category_item,parent,false);
return new CategoryViewHolder(view);
case EVENT_TYPE:
view = LayoutInflater.from(context).inflate(R.layout.events_item,parent,false);
return new EventViewHolder(view);
}
return null;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final Item item = allItems.get(position);
switch (item.getType()){
case CATEGORY_TYPE:
((CategoryViewHolder)holder).tvCategoryTitle.setText(item.getTitle());
((GradientDrawable)(((CategoryViewHolder)holder).categoryColorIcon).getBackground()).setColor(Color.parseColor(item.getColor()));
((CategoryViewHolder)holder).imgAddEvent.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
hideOrShowListener.setHideOrShow(item,false);
}
});
break;
case EVENT_TYPE:
String[] time = item.getTime().trim().split(":");
int hour = Integer.parseInt(time[0]);
((EventViewHolder)holder).tvEventName.setText(item.getTitle());
((EventViewHolder)holder).tvTime.setText(hour<12?hour+" : "+time[1] +" am" : hour-12+" : "+time[1] +" pm" );
((EventViewHolder)holder).tvPlace.setText(item.getPlace());
if(item.getDescription().length()==0) {
item.setDescription("No Detail");
}
((EventViewHolder)holder).tvDescription.setText(item.getDescription());
if(item.isShow()){
((EventViewHolder)holder).descriptionLayout.animate().alpha(1).setDuration(200).setInterpolator(new AccelerateInterpolator()).start();
((EventViewHolder)holder).descriptionLayout.setVisibility(View.VISIBLE);
((EventViewHolder)holder).descriptionLayout.setSelected(true);
((EventViewHolder)holder).tvEdit.setVisibility(View.VISIBLE);
((EventViewHolder)holder).eventContainer.setSelected(true);
}else{
((EventViewHolder)holder).descriptionLayout.setVisibility(View.GONE);
((EventViewHolder)holder).descriptionLayout.animate().alpha(0).setDuration(500).start();
((EventViewHolder)holder).descriptionLayout.setSelected(false);
((EventViewHolder)holder).eventContainer.setSelected(false);
((EventViewHolder)holder).tvEdit.setVisibility(View.INVISIBLE);
}
((EventViewHolder)holder).tvEdit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
hideOrShowListener.setHideOrShow(item,true);
}
});
break;
}
}
@Override
public int getItemCount() {
Log.d("c",allItems.size()+"");
return allItems.size();
}
@Override
public int getItemViewType(int position) {
if(allItems!=null){
return allItems.get(position).getType();
}
return 0;
}
public class CategoryViewHolder extends RecyclerView.ViewHolder{
private TextView tvCategoryTitle;
private View categoryColorIcon;
private ImageView imgAddEvent;
public CategoryViewHolder(View itemView) {
super(itemView);
tvCategoryTitle = (TextView) itemView.findViewById(R.id.tvCategoryTitle);
categoryColorIcon = itemView.findViewById(R.id.categoryColorIcon);
imgAddEvent = (ImageView) itemView.findViewById(R.id.addEvent);
}
}
public class EventViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private LinearLayout descriptionLayout;
private RelativeLayout eventContainer;
private TextView tvEventName,tvTime,tvPlace,tvDescription,tvEdit;
public EventViewHolder(View itemView) {
super(itemView);
descriptionLayout = (LinearLayout) itemView.findViewById(R.id.descriptionLayout);
eventContainer = (RelativeLayout) itemView.findViewById(R.id.eventContainer);
tvEventName = (TextView) itemView.findViewById(R.id.tvEventName);
tvTime = (TextView) itemView.findViewById(R.id.tvTime);
tvPlace = (TextView) itemView.findViewById(R.id.tvPlace);
tvDescription = (TextView) itemView.findViewById(R.id.tvDescription);
tvEdit = (TextView) itemView.findViewById(R.id.tvEdit);
eventContainer.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if(flag){
allItems.get(lastPosition).setShow(false);
}
allItems.get(getAdapterPosition()).setShow(true);
flag = true;
lastPosition = getAdapterPosition();
notifyDataSetChanged();
}
}
public interface HideOrShowListener{
public void setHideOrShow(Item item , boolean isEdit);
}
}
但是当我点击主页button并重新输入我的应用程序时，我的RecyclerView刷新了。这意味着notifyDatasetChanged方法中的onResume有效。但在我的刷新方法中，它并不起作用。我怎么能这样做？
答案 0 :(得分：0)
您确定要调用此方法：
@Override
public void onInserted() {
fragment.refresh();
}
确保您拥有正确的片段实例。或者您可以简单地使用refresh（）方法进行用户界面，并在片段中实现它。