问题描述
你好朋友很多搜索但没有工作请帮助我。 我的问题是使用工具栏上的删除图标从适配器中删除所有历史记录如何删除适配器数据 下面的代码首先显示适配器和主要活动 public void removehistory（查看视图） 按钮单击以从适配器中删除项目如何解决此问题抱歉英语不好并提前谢谢
历史适配器
public class HistoryAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private ArrayList<Object> data;
private GenCallback<HistoryModel> clickListener;
private static final int NATIVE_AD = 1;
private static final int HISTORY_ITEM = 2;
private LayoutInflater inflater;
// private Button removedata;
public HistoryAdapter() {
this.data = new ArrayList<>();
inflater = (LayoutInflater) App.getInstance().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent,int viewType) {
View view;
switch (viewType) {
case NATIVE_AD:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.ad_unified,null,false);
return new NativeAdHolder(view);
case HISTORY_ITEM:
default:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_history,false);
return new ViewHolder(view);
}
// return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_history,false));
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder,int position) {
switch (getItemViewType(position)) {
case NATIVE_AD:
((NativeAdHolder) holder).bind((UnifiednativeAd) data.get(position));
break;
case HISTORY_ITEM:
default:
((ViewHolder) holder).bind((HistoryModel) data.get(position));
break;
}
}
@Override
public int getItemViewType(int position) {
if (data.get(position) instanceof UnifiednativeAd) {
return NATIVE_AD;
} else {
return HISTORY_ITEM;
}
}
@Override
public int getItemCount() {
return data.size();
}
public void addItem(Object obj,int pos) {
this.data.add(pos,obj);
notifyItemInserted(pos);
}
public void updateData(ArrayList<HistoryModel> list) {
this.data.clear();
this.data.addAll(list);
notifyDataSetChanged();
}
public void clear() {
if (this.data != null && this.data.size() != 0) {
this.data.clear();
notifyDataSetChanged();
}
}
public void setClickListener(GenCallback<HistoryModel> clickListener) {
this.clickListener = clickListener;
}
public void showStarredOnly() {
/*Iterator<Object> iterator = data.iterator();
int pos = 0;
while (iterator.hasNext()) {
if (iterator.next() instanceof HistoryModel) {
HistoryModel historyModel = (HistoryModel) iterator.next();
if (!historyModel.isstarred()) {
iterator.remove();
// notifyItemRemoved(pos);
}
}
pos++;
}
notifyDataSetChanged();*/
}
public class ViewHolder extends RecyclerView.ViewHolder {
@BindView(R.id.tvFromLang)
TextView tvFromLang;
@BindView(R.id.tvFromText)
TextView tvFromText;
@BindView(R.id.tvToLang)
TextView tvToLang;
@BindView(R.id.tvToText)
TextView tvToText;
@BindView(R.id.ivstar)
ImageView ivstar;
@BindView(R.id.llMain)
CardView llMain;
@BindView(R.id.tvDate)
TextView tvDate;
public ViewHolder(@NonNull View itemView) {
super(itemView);
ButterKnife.bind(this,itemView);
llMain.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (clickListener != null) {
clickListener.onCallback((HistoryModel) data.get(getAdapterPosition()));
}
}
});
llMain.setonLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
int pos = getAdapterPosition();
HistoryModel historyModel = (HistoryModel) data.get(pos);
boolean isstar = historyModel.isstarred();
String from = historyModel.getFromLang();
String to = historyModel.getToLang();
Dialogs.INSTANCE.showActionsDialog(llMain.getContext(),isstar,from,to,new HistoryActionCallback() {
@Override
public void onClickcopyFrom() {
Utils.copyText(historyModel.getFromText());
Logger.logFabric(Constants.Events.copY_FROM);
}
@Override
public void onClickcopyTo() {
Utils.copyText(historyModel.getToText());
Logger.logFabric(Constants.Events.copY_TO);
}
@Override
public void onClickStar() {
Logger.logFabric(Constants.Events.MARKED_AS_FAV);
historyModel.setStarred(!isstar);
notifyItemChanged(pos);
Roomrepository.getNew().updateHistoryItem(historyModel);
// notifyDataSetChanged();
}
@Override
public void onClickDelete() {
String message = "Are you sure you want to delete?";
Dialogs.INSTANCE.showConfirmationDialog(view.getContext(),message,new View.OnClickListener() {
@Override
public void onClick(View view) {
Roomrepository.getNew().deleteHistoryRecord(historyModel.getTimeStamp());
data.remove(pos);
notifyItemRemoved(pos);
Dialogs.INSTANCE.dismissDialog();
Logger.logFabric(Constants.Events.ITEM_DELETED);
}
});
}
});
return false;
}
});
}
public void bind(HistoryModel item) {
StringBuilder builder = new StringBuilder();
builder.append(item.getFromLang()).append("(").append(item.getFromCode()).append(")");
tvFromLang.setText(builder);
tvFromText.setText(item.getFromText());
builder.setLength(0);
builder.append(item.getToLang()).append("(").append(item.getToCode()).append(")");
tvToLang.setText(builder);
tvToText.setText(item.getToText());
String date = Utils.formatDate(item.getTimeStamp(),"EEE,MMM d,yyyy");
tvDate.setText(date);
ivstar.setVisibility(item.isstarred() ? View.VISIBLE : View.GONE);
}
主活动
public class HistoryActivity extends AppCompatActivity {
private HistoryAdapter mAdapter;
private ArrayList<Object> data;
private Activity mCurrentActivity;
private RecyclerView rvHistory;
private Button clearh;
private GenCallback<HistoryModel> clickListener;
private ArrayList<HistoryModel> datamodel = new ArrayList<>();
private ArrayList<String> arrayList = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_history);
rvHistory = findViewById(R.id.rvHistory);
ImageView imgb = findViewById(R.id.imgback);
initAdapter();
getAdapter();
imgb.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
HistoryActivity.super.onBackpressed();
}
});
}
private void getAdapter() {
Roomrepository.getNew().getAllHistory(mCallback);
}
private void initAdapter() {
mAdapter = new HistoryAdapter();
linearlayoutmanager layoutManager = new linearlayoutmanager(mCurrentActivity);
rvHistory.setLayoutManager(layoutManager);
rvHistory.setAdapter(mAdapter);
}
private IRoomDataHandler mCallback = new RoomDataHandler() {
@Override
public void onGetAllHistory(ArrayList<HistoryModel> list) {
// if (isSafe()) {
mAdapter.updateData(list);
// showLoader(false);
// checkForNoData();
// if (AdUtils.getInstance().getNativeAd() != null) {
//
// }
}
@Override
public void onError(String error) {
// showLoader(false);
// checkForNoData();
}
};
public void removehistory(View view) {
//problem is here
mAdapter.notifyItemRemoved(i);
}
}
解决方法
在点击按钮时调用 clear() 方法，就像这样。
public void removehistory(View view) {
//problem is here
mAdapter.clear()
}