| page.title=Saving Data |
| |
| trainingnavtop=true |
| startpage=true |
| |
| @jd:body |
| |
| <div id="tb-wrapper"> |
| <div id="tb"> |
| |
| <h2>Dependencies and prerequisites</h2> |
| <ul> |
| <li>Android 1.6 (API Level 4) or higher</li> |
| <li>Familiarity with Map key-value collections</li> |
| <li>Familiarity with the Java file I/O API</li> |
| <li>Familiarity with SQL databases</li> |
| </ul> |
| |
| <h2>You should also read</h2> |
| <ul> |
| <li><a href="{@docRoot}guide/topics/data/data-storage.html">Storage Options</a></li> |
| </ul> |
| |
| </div> |
| </div> |
| |
| <p>Most Android apps need to save data, even if only to save information about the app state |
| during {@link android.app.Activity#onPause onPause()} so the user's progress is not lost. Most |
| non-trivial apps also need to save user settings, and some apps must manage large |
| amounts of information in files and databases. This class introduces you to the |
| principal data storage options in Android, including:</p> |
| |
| <ul> |
| <li>Saving key-value pairs of simple data types in a shared preferences |
| file</li> |
| <li>Saving arbitrary files in Android's file system</li> |
| <li>Using databases managed by SQLite</li> |
| </ul> |
| |
| |
| <h2>Lessons</h2> |
| |
| <dl> |
| <dt><b><a href="shared-preferences.html">Saving Key-Value Sets</a></b></dt> |
| <dd>Learn to use a shared preferences file for storing small amounts of information in |
| key-value pairs.</dd> |
| |
| <dt><b><a href="files.html">Saving Files</a></b></dt> |
| <dd>Learn to save a basic file, such as to store long sequences of data that |
| are generally read in order.</dd> |
| |
| <dt><b><a href="databases.html">Saving Data in SQL Databases</a></b></dt> |
| <dd>Learn to use a SQLite database to read and write structured data.</dd> |
| |
| </dl> |