本文介绍了在recyclerView中突出显示过滤的文本的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
这是我的适配器类:
public class adapter_cgpa extends RecyclerView.Adapter<adapter_cgpa.Viewholder> implements Filterable {
ArrayList<POJO> cgpaArrayList;
ArrayList<POJO> cgpaArrayListcopy;
String filterPattern = "";
public adapter_cgpa(ArrayList<POJO> cgpaArrayList) {
this.cgpaArrayList = cgpaArrayList;
cgpaArrayListcopy = new ArrayList<>(cgpaArrayList);
}
@NonNull
@Override
public adapter_cgpa.Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View listitem = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_cgpa, parent, false);
return new Viewholder(listitem);
}
@Override
public void onBindViewHolder(@NonNull adapter_cgpa.Viewholder holder, int position) {
POJO cgpa = cgpaArrayList.get(position);
if (!filterPattern.equals("")) {
String tmpCname = cgpa.getCname();
int startPos = tmpCname.toLowerCase(Locale.US).indexOf(filterPattern.toLowerCase(Locale.US));
int endPos = startPos + filterPattern.length();
if (startPos != -1) {
Spannable spannable = new SpannableString(tmpCname);
ColorStateList blueColor = new ColorStateList(new int[][]{new int[]{}}, new int[]{Color.BLUE});
TextAppearanceSpan highlightSpan = new TextAppearanceSpan(null, Typeface.BOLD, -1, blueColor, null);
spannable.setSpan(highlightSpan, startPos, endPos, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
holder.cname.setText(spannable);
} else {
holder.cname.setText(cgpa.getCname());
}
} else {
holder.cname.setText(cgpa.getCname());
}
holder.no_of_sems.setText(cgpa.getNo_of_sems());
holder.cgpa.setText(cgpa.getCgpa());
holder.percentage.setText(cgpa.getPercentage());
holder.schemec.setText(cgpa.getSchemec());
}
@Override
public int getItemCount() {
return cgpaArrayList.size();
}
@Override
public Filter getFilter() {
return new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
List<POJO> filteredList = new ArrayList<>();
if (TextUtils.isEmpty(constraint)) {
filterPattern="";
filteredList.addAll(cgpaArrayListcopy);
} else {
filterPattern = constraint.toString().toLowerCase().trim();
for (POJO item : cgpaArrayListcopy) {
if (item.getCname().toLowerCase().contains(filterPattern)) {
filteredList.add(item);
// } else {
// filteredList.remove(item);
}
}
}
FilterResults results = new FilterResults();
results.values = filteredList;
return results;
}
@Override
public void publishResults(CharSequence constraint, FilterResults results) {
cgpaArrayList.clear();
cgpaArrayList.addAll((List) results.values);
notifyDataSetChanged();
}
};
}
public class Viewholder extends RecyclerView.ViewHolder {
TextView cname, no_of_sems, cgpa, percentage, schemec;
ImageButton btndelete2;
public Viewholder(@NonNull View itemView) {
super(itemView);
cname = itemView.findViewById(R.id.name);
no_of_sems = itemView.findViewById(R.id.no_of_sem);
cgpa = itemView.findViewById(R.id.textView49);
percentage = itemView.findViewById(R.id.textView55);
schemec = itemView.findViewById(R.id.scheme2);
btndelete2 = itemView.findViewById(R.id.btndelete2);
btndelete2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final AlertDialog.Builder alert = new AlertDialog.Builder(v.getContext());
alert.setMessage("Are you sure you want to delete this?");
alert.setNegativeButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
}
});
alert.setPositiveButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
}
});
final AlertDialog dialogs = alert.create();
dialogs.show();
dialogs.getButton(androidx.appcompat.app.AlertDialog.BUTTON_NEGATIVE).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
delete(getAdapterPosition());
dialogs.dismiss();
}
});
dialogs.getButton(androidx.appcompat.app.AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
dialogs.dismiss();
}
});
}
});
}
private void delete(int adapterPosition) {
cgpaArrayList.remove(adapterPosition);
notifyDataSetChanged();
final String snc = cname.getText().toString();
final String semrc = no_of_sems.getText().toString();
final String schc = schemec.getText().toString();
dbmanager db = new dbmanager(itemView.getContext());
db.delete2(snc, semrc, schc);
}
}
这是我的cgpa_frag片段:
And this is my cgpa_frag fragment:
public class cgpa_frag extends Fragment {
RecyclerView recyclerview;
adapter_cgpa ac;
TextView tv_noContent2;
ArrayList<POJO> cgpaArrayList = new ArrayList<>();
public cgpa_frag() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
setHasOptionsMenu(true);
View view = inflater.inflate(R.layout.fragment_cgpa_frag, container, false);
recyclerview = (RecyclerView) view.findViewById(R.id.rc2);
tv_noContent2 = (TextView)view.findViewById(R.id.tv_noContent2);
cgpaArrayList = new ArrayList<>();
Fetchdata2();
ac = new adapter_cgpa(cgpaArrayList);
recyclerview.setLayoutManager(new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false));
if(cgpaArrayList.isEmpty()){
recyclerview.setVisibility(View.GONE);
tv_noContent2.setVisibility(View.VISIBLE);
tv_noContent2.setText("Look's like you have not saved any CGPA calculation.");
}else{
tv_noContent2.setVisibility(View.GONE);
recyclerview.setVisibility(View.VISIBLE);
recyclerview.setAdapter(ac);
}
return view;
}
private void Fetchdata2() {
dbmanager db = new dbmanager(getContext());
Cursor cursor = db.fetch_data2();
if (cursor != null) {
while (cursor.moveToNext()) {
POJO pj = new POJO();
pj.setCname(cursor.getString(0));
pj.setNo_of_sems(cursor.getString(1));
pj.setCgpa(cursor.getString(2));
pj.setPercentage(cursor.getString(3));
pj.setSchemec(cursor.getString(4));
cgpaArrayList.add(pj);
}
// ac = new adapter_cgpa(cgpaArrayList);
}
}
@Override
public void onCreateOptionsMenu(@NonNull Menu menu, @NonNull MenuInflater inflater) {
inflater.inflate(R.menu.search_menu, menu);
MenuItem searchItem = menu.findItem(R.id.action_search);
SearchView searchView = (SearchView) searchItem.getActionView();
searchView.onActionViewExpanded();
searchView.setIconifiedByDefault(false);
searchView.setQueryHint("Search by name ... ");
if(!searchView.isFocused()) {
searchView.clearFocus();
}
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
ac.getFilter().filter(newText, new Filter.FilterListener() {
@Override
public void onFilterComplete(int i) {
if(i == 0){
recyclerview.setVisibility(View.GONE);
tv_noContent2.setVisibility(View.VISIBLE);
tv_noContent2.setText("No matching results found");
}else{
tv_noContent2.setVisibility(View.GONE);
recyclerview.setVisibility(View.VISIBLE);
}
}
});
return false;
}
});
}
如何从bindviewHolder中的getFilter方法访问filterPattern?我想知道如何从bindviewHolder中的getFilter方法访问filterPattern，以便能够在RecyclerView中突出显示匹配的文本模式.有人可以帮我吗?预先感谢.
How can I access filterPattern from getFilter method in bindviewHolder ? I wanted to know how can I access filterPattern from getFilter method in bindviewHolder so that I am able to highlight the matching text patterns in RecyclerView. Can anyone help me with it ? Thanks in advance.
推荐答案
在ArrayList<POJO> cgpaArrayListcopy;之后添加String filterPattern = "";，然后可以在适配器中的任何位置访问 filterPattern .
Add String filterPattern = ""; after ArrayList<POJO> cgpaArrayListcopy;, then filterPattern can be accessed everywhere in the adapter.
要突出显示过滤的文本，请尝试以下代码:
To highlight filtered text, try the following codes:
@Override
public void onBindViewHolder(@NonNull adapter_cgpa.Viewholder holder, int position) {
POJO cgpa = cgpaArrayList.get(position);
if (!filterPattern.equals("")) {
String tmpCname = cgpa.getCname();
int startPos = tmpCname.toLowerCase(Locale.US).indexOf(filterPattern.toLowerCase(Locale.US));
int endPos = startPos + filterPattern.length();
if (startPos != -1) {
Spannable spannable = new SpannableString(tmpCname);
ColorStateList blueColor = new ColorStateList(new int[][]{new int[]{}}, new int[]{Color.BLUE});
TextAppearanceSpan highlightSpan = new TextAppearanceSpan(null, Typeface.BOLD, -1, blueColor, null);
spannable.setSpan(highlightSpan, startPos, endPos, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
holder.cname.setText(spannable);
} else {
holder.cname.setText(cgpa.getCname());
}
} else {
holder.cname.setText(cgpa.getCname());
}
holder.no_of_sems.setText(cgpa.getNo_of_sems());
holder.cgpa.setText(cgpa.getCgpa());
holder.percentage.setText(cgpa.getPercentage());
holder.schemec.setText(cgpa.getSchemec());
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
List<POJO> filteredList = new ArrayList<>();
if (TextUtils.isEmpty(constraint)) {
filterPattern = "";
filteredList.addAll(cgpaArrayListcopy);
} else {
filterPattern = constraint.toString().toLowerCase().trim();
for (POJO item : cgpaArrayListcopy) {
if (item.getCname().toLowerCase().contains(filterPattern)) {
filteredList.add(item);
//} else {
// filteredList.remove(item);
}
}
}
FilterResults results = new FilterResults();
results.values = filteredList;
results.count = filteredList.size();
return results;
}
希望有帮助！
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