我的 getFilter() 方法有错误吗？

Posted 2023-04-19

【中文标题】我的 getFilter() 方法有错误吗？

【英文标题】：Is there an error in my getFilter() method?

【发布时间】：2020-06-14 09:35:10

【问题描述】：

我正在开发一个管理联系人的基本 android 应用程序。我正在使用自定义适配器和自定义列表视图。我有一个代表每个联系人的类 ContactItem。列表视图的每个联系人都是一个 ContactItem 实例。当我实现我的搜索视图时，应用程序崩溃了。我遵循了answer，但每次我在搜索中写入以过滤列表视图时，应用程序都会崩溃。

我希望能得到一些支持，因为自 2 月以来我一直在努力寻找解决方案。 这是我的适配器：

public class CustomAdapter extends ArrayAdapter<ContactItem> implements Filterable 

    private Context context;
    private ArrayList<ContactItem> arrayList;

    public CustomAdapter(@NonNull Context context, int resource, ArrayList<ContactItem> arrayList) 
        super(context, resource, arrayList);

        this.context = context;
        this.arrayList = arrayList;
    

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) 
        View view = convertView;
        LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        view = layoutInflater.inflate(R.layout.customlist, parent, false);
        TextView nom = (TextView) view.findViewById(R.id.nom);

        String nomComplet = arrayList.get(position).getPrenom() + " " +arrayList.get(position).getNom();
        nom.setText(nomComplet);

        return view;
    

    Filter myFilter = new Filter() 
        @Override
        protected FilterResults performFiltering(CharSequence constraint) 

            FilterResults filterResults = new FilterResults();
            ArrayList<ContactItem> templist = new ArrayList<ContactItem>();

            //constraint is the text you want to filter your list with
            //arraylist is the data set we will filter from
            if(constraint != null && arrayList !=null)
                int length = arrayList.size();
                int i ;
                String nomComplet;
                Integer id;
                String nom, prenom,phone,adresse,email;

                for(i=0;i<length;i++)


                    nomComplet = arrayList.get(i).getNom()+" "+ arrayList.get(i).getPrenom();

                    if(nomComplet.toUpperCase().contains(constraint.toString().toUpperCase()))
                        ContactItem item = (ContactItem) arrayList.get(i);
                        templist.add(item);


                    

                
                filterResults.values = templist;
                filterResults.count = templist.size();
            else 
                filterResults.values = arrayList;
                filterResults.count = arrayList.size();
            

            return filterResults;
        

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) 

                arrayList = (ArrayList<ContactItem>) results.values;
                if(results.count>0)
                    notifyDataSetChanged();
                else
                    notifyDataSetInvalidated();
                
        
    ;
    @NonNull
    @Override
    public Filter getFilter() 
        return myFilter;
    

【问题讨论】：

你能在这里分享你的xml吗

【参考方案1】：

请检查这个

  Filter myFilter = new Filter() 
            @Override
            protected FilterResults performFiltering(CharSequence constraint) 
             FilterResults filterResults = new FilterResults();   
             ArrayList<ContactItem> tempList=new ArrayList<ContactItem>();
             //constraint is the result from text you want to filter against. 
             //objects is your data set you will filter from
             if(constraint != null && objects!=null) 
                 int length=objects.size();
                 int i=0;
                    while(i<length)
                        ListTO item=objects.get(i);
                        //do whatever you wanna do here
                        //adding result set output array     

                        tempList.add(item);

                        i++;
                    
                    //following two lines is very important
                    //as publish result can only take FilterResults objects
                    filterResults.values = tempList;
                    filterResults.count = tempList.size();
              
              return filterResults;
          

      @SuppressWarnings("unchecked")
      @Override
      protected void publishResults(CharSequence contraint, FilterResults results) 
          objects = (ArrayList<ContactItem>) results.values;
          if (results.count > 0) 
           notifyDataSetChanged();
           else 
              notifyDataSetInvalidated();
            
      
     ;

最后一步，

@Override
     public Filter getFilter() 
        return myFilter;
    

【讨论】：

感谢您的回答，但我看不出您的建议与我的建议有何不同。你能解释一下我做错了什么吗？