PreferencesWithDefaultsActivity.java

package com.google.mcommerce.sample.android.chapter07.preferences;

// This file is MainActivity.java
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.TextView;

import com.google.mcommerce.sample.android.R;

public class PreferencesWithDefaultsActivity extends Activity {
	private Resources resources;
	private SharedPreferences prefs;
	private TextView tv = null;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.c07_preferences_layout);

		resources = this.getResources();
		// 获得默认的preference对象
		prefs = PreferenceManager.getDefaultSharedPreferences(this);
		Log.i("PreferencesWithDefaultsActivity", "0");
		// prefs.edit().clear().commit();
		// 在应用目录中设置配置文件缺省值
		PreferenceManager.setDefaultValues(this, R.xml.flightoptions_single,
				false);
		Log.i("PreferencesWithDefaultsActivity", "1");

		tv = (TextView) findViewById(R.id.text1);

		setOptionText();
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		MenuInflater inflater = getMenuInflater();
		inflater.inflate(R.menu.mainmenu, menu);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		if (item.getItemId() == R.id.menu_prefs) {
			Intent intent = new Intent().setClass(this,
					FlightPreferenceSingle.class);
			this.startActivityForResult(intent, 0);
		}
		return true;
	}

	@Override
	public void onActivityResult(int reqCode, int resCode, Intent data) {
		super.onActivityResult(reqCode, resCode, data);
		setOptionText();
	}

	private void setOptionText() {
		String option = prefs
				.getString(resources
						.getString(R.string.selected_flight_sort_option), null);
		String[] optionText = resources
				.getStringArray(R.array.flight_sort_options);

		tv.setText("option value is " + option + " ("
				+ optionText[Integer.parseInt(option)] + ")");
	}
}