Autocompletetextview with custom adapter and filter(Autocompletetextview 用户自定义下拉框样式)

在Activity中添加一行代码即可：

main_search_autoCompleteTextView.setAdapter(new MainSearchAutoEditTextViewAdapter3(MainSearchActivity3.strList,MainActivity.this));

自定义的BaseAdapter的实现：MainSearchAutoEditTextViewAdapter3.java

import android.content.Context;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.Filter;import android.widget.Filterable;import android.widget.TextView;import java.util.ArrayList;import java.util.List;import cn.com.amway.bokuhk.R;//要implements Filterable，目的是：顾名思义就是下拉提示的是与你输入关键字有关的内容（对所有存在的内容进行过滤，过滤出与你输入关键字有关部分）public class MainSearchAutoEditTextViewAdapter3 extends BaseAdapter implements Filterable {

    //list是用来显示下拉内容的    private List<String> list;    private Context context;

    //过滤器（实现过滤功能的对象）    private Filter filter;

    //tempItems：所有的内容集合

   //suggestions：中间变量（在后台过滤时用的到，因为每次更换关键字进行过滤时都会用的到，所以称为中间变量）

    List<String> tempItems, suggestions;    public MainSearchAutoEditTextViewAdapter3(List<String> list, Context context) {        this.list = list;        this.context = context;        tempItems = new ArrayList<String>(list); // this makes the difference.        suggestions = new ArrayList<String>();    }    @Override    public int getCount() {        return this.list == null ? 0 : list.size();    }

    //注意：不能反悔为空，否则点击下拉选项的某一项时没有反应    @Override    public long getItemId(int position) {        return position;    }

    
   //注意：不能反悔为空，否则点击下拉选项的某一项时没有反应
    @Override    public String getItem(int position) {        return list.get(position);    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        View viewTemp = View.inflate(this.context, R.layout.item_autotextview_mainsearch, null);        TextView textView = (TextView)viewTemp.findViewById(R.id.main_search_item_tv);        textView.setText(this.list.get(position));        return viewTemp;    }    @Override    public Filter getFilter() {        if(this.filter == null) {            this.filter = new MyFilter();        }        return this.filter;    }    class MyFilter extends Filter {//把对象转换为字符串        @Override        public CharSequence convertResultToString(Object resultValue) {            String str = ((String) resultValue);            return str;        }

        //在后台选出与关键字相关的 内容list        @Override        protected FilterResults performFiltering(CharSequence constraint) {            if (constraint != null) {                suggestions.clear();                for (String str : tempItems) {                    if (str.toLowerCase().contains(constraint.toString().toLowerCase())) {                        suggestions.add(str);                    }                }                FilterResults filterResults = new FilterResults();

//内容list                filterResults.values = suggestions;                filterResults.count = suggestions.size();                return filterResults;            } else {                return new FilterResults();            }        }

//在UI展示下拉结果（该方法的两个形参就是上面重写的两个函数的返回值）        @Override        protected void publishResults(CharSequence constraint, FilterResults results) {            List<String> filterList = (ArrayList<String>) results.values;            if (results != null && results.count > 0) {                list = filterList;                notifyDataSetChanged();            } else {                list = new ArrayList<>();                notifyDataSetInvalidated();            }        }    }}

-------------------------/layout/main_search_item_tv.xml------------------------------

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal"    >    <TextView        android:id="@+id/main_search_item_tv"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="36dp"        /></LinearLayout>