虽然不难，但是容易忘记，做个备忘吧

package com.guet.zhuge;  import android.app.Activity;import android.os.Bundle;import android.text.Editable;import android.text.TextWatcher;import android.widget.AutoCompleteTextView;  public class MainActivity extends Activity implements TextWatcher{          private AutoCompleteTextView autoview;        private AutoTextViewAdapter adapter;                  private static final String[] AUTO_EMAILS = {"@163.com", "@sina.com", "@qq.com", "@126.com", "@gmail.com", "@apple.com"};                  @Override        protected void onCreate(Bundle savedInstanceState) {                super.onCreate(savedInstanceState);                setContentView(R.layout.activity_main);                autoview = (AutoCompleteTextView) findViewById(R.id.auto_tv);                adapter = new AutoTextViewAdapter(this);                autoview.setAdapter(adapter);                autoview.setThreshold(1);//输入1个字符时就开始检测，默认为2个                autoview.addTextChangedListener(this);//监听autoview的变化        }          @Override        public void afterTextChanged(Editable s) {                // TODO Auto-generated method stub                String input = s.toString();          adapter.mList.clear();          autoAddEmails(input);        adapter.notifyDataSetChanged();          autoview.showDropDown();          }                  /**         * 自动填充邮箱列表         * @param input         */        private void autoAddEmails(String input) {                System.out.println("input-->" + input);                String autoEmail = "";        if (input.length() > 0) {              for (int i = 0; i < AUTO_EMAILS.length; ++i) {                      if(input.contains("@")) {
   //包含“@”则开始过滤                            String filter = input.substring(input.indexOf("@") + 1 , input.length());//获取过滤器，即根据输入“@”之后的内容过滤出符合条件的邮箱                            System.out.println("filter-->" + filter);                            if(AUTO_EMAILS[i].contains(filter)) {
   //符合过滤条件                                    autoEmail = input.substring(0, input.indexOf("@")) + AUTO_EMAILS[i];//用户输入“@”之前的内容加上自动填充的内容即为最后的结果                                    adapter.mList.add(autoEmail);                            }                    }else {                            autoEmail = input + AUTO_EMAILS[i];                            adapter.mList.add(autoEmail);                    }            }          }        }          @Override        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,                        int arg3) {                // TODO Auto-generated method stub                          }          @Override        public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {                // TODO Auto-generated method stub                          }}

适配器代码如下：

package com.guet.zhuge;  import java.util.ArrayList;import java.util.List;  import android.content.Context;import android.graphics.Color;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.Filter;import android.widget.Filterable;import android.widget.TextView;    public class AutoTextViewAdapter extends BaseAdapter implements Filterable {                      public List
     
       mList;      private Context mContext;      private MyFilter mFilter;              public AutoTextViewAdapter(Context context) {          mContext = context;          mList = new ArrayList
      
       ();      }              @Override      public int getCount() {          return mList == null ? 0 : mList.size();      }        @Override      public Object getItem(int position) {          return mList == null ? null : mList.get(position);      }        @Override      public long getItemId(int position) {          return position;      }        @Override      public View getView(int position, View convertView, ViewGroup parent) {          if (convertView == null) {              TextView tv = new TextView(mContext);              tv.setTextColor(Color.BLACK);              tv.setTextSize(20);              convertView = tv;          }          TextView txt = (TextView) convertView;          txt.setText(mList.get(position));          return txt;      }        public Filter getFilter() {          if (mFilter == null) {              mFilter = new MyFilter();          }          return mFilter;      }            private class MyFilter extends Filter {                            @Override              protected FilterResults performFiltering(CharSequence constraint) {                      FilterResults results = new FilterResults();                      if (mList == null) {                              mList = new ArrayList
       
        ();                      }                      results.values = mList;                      results.count = mList.size();                      return results;              }                            @Override              protected void publishResults(CharSequence constraint, FilterResults results) {                      if (results.count > 0) {                              notifyDataSetChanged();                      } else {                              notifyDataSetInvalidated();                      }              }                    }  }
       
      
     

主要的xml 部分文件：

 

 

继续学习！