在notifyDataSetChanged 上未调用GetView，ListView 卡住

如何解决在notifyDataSetChanged 上未调用GetView，ListView 卡住

我遇到了一个问题，我在联系人应用程序中创建了带有自定义筛选的自定义适配器，它可以很好地筛选联系人姓名，并且已正确保存已过滤的联系人列表。问题是，当我在 searchView 中输入任何内容时，找到的行数是正确的，但有关找到的行的信息不正确。问题似乎与适配器中的 getView 函数有关，它在应该调用时没有调用。例如，如果我有三个联系人：“abc”、“aaa”、“aba”，并且它们按从上到下的顺序显示在开始处，那么如果我在 searchView 中键入“ab”，则它会找到 2 行，但它们仍然与开始时相同，它们应该是“abc”和“aba”，但它们是“abc”和“aaa”。适配器创建的第一个视图似乎由于某种原因卡住了。

我的活动课：

package com.example.androidlab;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import androidx.appcompat.app.AppCompatActivity;

import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.Toast;

import java.lang.reflect.Type;
import java.util.ArrayList;

public class AllContactsActivity extends AppCompatActivity {
    static ArrayList<Contact> contacts = new ArrayList<>();
    ContactsAdapter contactsAdapter;

    ListView listView;
    SearchView searchView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_all_contacts);

        FloatingActionButton addContact = findViewById(R.id.newContact);

        listView = findViewById(R.id.allContactsList);
        searchView = findViewById(R.id.searchContacts);

        SharedPreferences sharedPreferences = getApplicationContext().getSharedPreferences("com.tanay.thunderbird.contacts",Context.MODE_PRIVATE);
        Gson gson = new Gson();
        String json = sharedPreferences.getString("contacts",null);
        Type type = new TypeToken<ArrayList<Contact>>() {
        }.getType();
        contacts = gson.fromJson(json,type);
        if (contacts == null) {
            contacts = new ArrayList<>();
        }
        if (contacts.size() == 0)
            Toast.makeText(this,"There are no contacts.",Toast.LENGTH_LONG).show();

        contactsAdapter = new ContactsAdapter(this,contacts);
        listView.setAdapter(contactsAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent,View view,int position,long id) {
                Intent intent = new Intent(getApplicationContext(),EditContactActivity.class);
                intent.putExtra("noteID",position);
                startActivity(intent);
                finish();
            }
        });

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                contactsAdapter.getFilter().filter(query);
                return false;
            }

            @Override
            public boolean onQueryTextChange(String query) {
                contactsAdapter.getFilter().filter(query);
                return false;
            }
        });

        addContact.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getApplicationContext(),NewContactActivity.class);
                startActivity(intent);
                finish();
            }
        });

    }


    @Override
    public void onBackPressed() {
        finish();
    }
}

我的适配器类：

package com.example.androidlab;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Base64;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class ContactsAdapter extends BaseAdapter implements Filterable {

    Context context;
    List<Contact> contacts;
    List<Contact> filteredContacts;
    ContactFilter mFilter = new ContactFilter();
    String filterString;

    ContactsAdapter(Context context,List<Contact> contacts) {
        this.context = context;
        this.contacts = contacts;
        filteredContacts = contacts;
    }

    @Override
    public int getCount() {
        if(contacts.size() != filteredContacts.size() || filterString != null)
        {
            return filteredContacts.size();
        }
        else {
            filteredContacts = contacts;
            return contacts.size();
        }
    }

    @Override
    public Object getItem(int position) {
        return contacts.get(position);
    }

    @Override
    public long getItemId(int position) {
        return contacts.indexOf(getItem(position));
    }

    @Override
    public Filter getFilter() {
        return mFilter;
    }

    private class ViewHolder {
        ImageView imageView;
        TextView name;
        TextView phoneNumber;
    }

    @Override
    public View getView(int position,View convertView,ViewGroup parent) {
        ViewHolder holder = null;
            LayoutInflater mInflater = (LayoutInflater) context.getSystemService(AllContactsActivity.LAYOUT_INFLATER_SERVICE);
            if (convertView == null) {
                convertView = mInflater.inflate(R.layout.list_contacts,null);
                holder = new ViewHolder();

                holder.name = (TextView) convertView.findViewById(R.id.contactName);
                holder.imageView = (ImageView) convertView.findViewById(R.id.imageOfContact);
                holder.phoneNumber = (TextView) convertView.findViewById(R.id.phoneNumber);

                Contact contact;

                if(filteredContacts.size() != contacts.size()) contact = filteredContacts.get(position);
                else contact = contacts.get(position);

                if (contact.getAvatar() == null) {
                    if (contact.getGender() == true)
                        holder.imageView.setImageResource(R.drawable.ic_man);
                    else holder.imageView.setImageResource(R.drawable.ic_woman);
                } else {
                    byte[] decodedString = Base64.decode(contact.getAvatar(),Base64.DEFAULT);
                    Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString,decodedString.length);
                    holder.imageView.setImageBitmap(decodedByte);
                }
                holder.name.setText(contact.getName());
                holder.phoneNumber.setText(String.valueOf(contact.getPhoneNumber()));
            }

        return convertView;
    }

    private class ContactFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {

            filterString = constraint.toString().toLowerCase();

            FilterResults results = new FilterResults();

            final List<Contact> list = contacts;

            int count = list.size();
            final ArrayList<Contact> nList = new ArrayList<Contact>();

            for (int i = 0; i < count; i++) {
                if(contacts.get(i).getName().contains(filterString)) nList.add(contacts.get(i));
            }

            results.values = nList;
            results.count = nList.size();
            return results;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint,FilterResults results) {
            filteredContacts = (ArrayList<Contact>) results.values;
            notifyDataSetChanged();
        }

    }
}

编辑：我在 getView 函数中去掉了 if(contentView == null) 并且一切正常

解决方法

对 convertView == null 的检查应该只处理 View 的膨胀和新 ViewHolder 的创建，其余的 getView 代码应该始终运行。>

public View getView(int position,View convertView,ViewGroup parent) { 
    ViewHolder holder; 

    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.list_contacts,null);
        // attach a new holder to the inflated view
        holder = new ViewHolder(); 
        convertView.setTag(holder); 
    } else { 
        // get an existing holder from the existing view
        holder = (ViewHolder) convertView.getTag(); 
    } 

    // update your holder here:
    // e.g. holder.name.setText(contact.getName());
    
    return convertView; 
}

在notifyDataSetChanged 上未调用GetView，ListView 卡住

如何解决在notifyDataSetChanged 上未调用GetView，ListView 卡住

解决方法

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