AutoCompelet vs ArrayAdapter 動態建立

import android.app.Activity;

import android.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.AutoCompleteTextView;

public class AutoCompleteActivity extends Activity {

        @Override

        protected void onCreate(Bundle savedInstanceState) {

                super.onCreate(savedInstanceState);

                setContentView(R.layout.activity_auto_complete);

                if (savedInstanceState == null) {

                        getFragmentManager().beginTransaction()

                                        .add(R.id.container, new PlaceholderFragment()).commit();

                }

        }

        @Override

        public boolean onCreateOptionsMenu(Menu menu) {

                // Inflate the menu; this adds items to the action bar if it is present.

                getMenuInflater().inflate(R.menu.auto_complete, menu);

                return true;

        }

        @Override

        public boolean onOptionsItemSelected(MenuItem item) {

                // Handle action bar item clicks here. The action bar will

                // automatically handle clicks on the Home/Up button, so long

                // as you specify a parent activity in AndroidManifest.xml.

                int id = item.getItemId();

                if (id == R.id.action_settings) {

                        return true;

                }

                return super.onOptionsItemSelected(item);

        }

        /**

         * A placeholder fragment containing a simple view.

         */

        public static class PlaceholderFragment extends Fragment {

                private String[] presidents={

                                "Dwight D. Eisenhower",

                                "John F. Kennedy",

                                "Lyndon B. Johnson",

                                "Richard Nixon",

                                "Gerald Ford",

                                "Jimmy Carter",

                                "Ronald Reagan",

                                "George H. W. Bush",

                                "Bill Clinton",

                                "George W. Bush",

                                "Barack Obama"

                };

                public PlaceholderFragment() {

                }

                @Override

                public View onCreateView(LayoutInflater inflater, ViewGroup container,

                                Bundle savedInstanceState) {

                        View rootView = inflater.inflate(R.layout.fragment_auto_complete,

                                        container, false);

                        ArrayAdapter<String> adapter=new ArrayAdapter<String>(

                                        PlaceholderFragment.this.getActivity(),

                                        android.R.layout.simple_dropdown_item_1line,

                                        presidents);

                        AutoCompleteTextView textView=(AutoCompleteTextView)rootView.findViewById(R.id.txtCountries);

                        textView.setThreshold(3);

                        textView.setAdapter(adapter);

                        return rootView;

                }

        }

}