1 page.title=Application Resources 2 @jd:body 3 4 <div id="qv-wrapper"> 5 <div id="qv"> 6 <h2>Topics</h2> 7 <ol> 8 <li><a href="providing-resources.html">Providing Resources</a></li> 9 <li><a href="accessing-resources.html">Accessing Resources</a></li> 10 <li><a href="runtime-changes.html">Handling Runtime Changes</a></li> 11 <li><a href="localization.html">Localization</a></li> 12 </ol> 13 14 <h2>Reference</h2> 15 <ol> 16 <li><a href="available-resources.html">Resource Types</a></li> 17 </ol> 18 </div> 19 </div> 20 21 22 <p>You should always externalize resources such as images and strings from your application 23 code, so that you can maintain them independently. Externalizing your 24 resources also allows you to provide alternative resources that support specific device 25 configurations such as different languages or screen sizes, which becomes increasingly 26 important as more Android-powered devices become available with different configurations. In order 27 to provide this functionality, you must organize resources in your project's {@code res/} 28 directory, using various sub-directories that group resources by type and configuration.</p> 29 30 <div class="figure" style="width:421px"> 31 <img src="{@docRoot}images/resources/resource_devices_diagram1.png" height="137" alt="" /> 32 <p class="img-caption"> 33 <strong>Figure 1.</strong> Two device configurations, both using default 34 resources.</p> 35 </div> 36 37 <div class="figure" style="width:421px"> 38 <img src="{@docRoot}images/resources/resource_devices_diagram2.png" height="137" alt="" /> 39 <p class="img-caption"> 40 <strong>Figure 2.</strong> Two device configurations, one using alternative 41 resources.</p> 42 </div> 43 44 <p>For any type of resource, you can specify <em>default</em> and multiple 45 <em>alternative</em> resources for your application:</p> 46 <ul> 47 <li>Default resources are those that should be used regardless of 48 the device configuration or when there are no alternative resources that match the current 49 configuration.</li> 50 <li>Alternative resources are those that you've designed for use with a specific 51 configuration. To specify that a group of resources are for a specific configuration, 52 append an appropriate configuration qualifier to the directory name.</li> 53 </ul> 54 55 <p>For example, while your default UI 56 layout is saved in the {@code res/layout/} directory, you might specify a different UI layout to 57 be used when the screen is in landscape orientation, by saving it in the {@code res/layout-land/} 58 directory. The Android system will automatically apply the appropriate resources by matching the 59 device's current configuration to your resource directory names.</p> 60 61 <p>Figure 1 demonstrates how a collection of default resources from an application will be applied 62 to two different devices when there are no alternative resources available. Figure 2 shows 63 the same application with a set of alternative resources that qualify for one of the device 64 configurations, thus, the two devices uses different resources.</p> 65 66 <p>The information above is just an introduction to how application resources work on Android. 67 The following documents provide a complete guide to how you can organize your application resources, 68 specify alternative resources, access them in your application, and more:</p> 69 70 <dl> 71 <dt><strong><a href="providing-resources.html">Providing Resources</a></strong></dt> 72 <dd>What kinds of resources you can provide in your app, where to save them, and how to create 73 alternative resources for specific device configurations.</dd> 74 <dt><strong><a href="accessing-resources.html">Accessing Resources</a></strong></dt> 75 <dd>How to use the resources you've provided, either by referencing them from your application 76 code or from other XML resources.</dd> 77 <dt><strong><a href="runtime-changes.html">Handling Runtime Changes</a></strong></dt> 78 <dd>How to manage configuration changes that occur while your Activity is running.</dd> 79 <dt><strong><a href="localization.html">Localization</a></strong></dt> 80 <dd>A bottom-up guide to localizing your application using alternative resources. While this is 81 just one specific use of alternative resources, it is very important in order to reach more 82 users.</dd> 83 <dt><strong><a href="available-resources.html">Resource Types</a></strong></dt> 84 <dd>A reference of various resource types you can provide, describing their XML elements, 85 attributes, and syntax. For example, this reference shows you how to create a resource for 86 application menus, drawables, animations, and more.</dd> 87 </dl> 88 89 <!-- 90 <h2>Raw Assets</h2> 91 92 <p>An alternative to saving files in {@code res/} is to save files in the {@code 93 assets/} directory. This should only be necessary if you need direct access to original files and 94 directories by name. Files saved in the {@code assets/} directory will not be given a resource 95 ID, so you can't reference them through the {@code R} class or from XML resources. Instead, you can 96 query data in the {@code assets/} directory like an ordinary file system, search through the 97 directory and 98 read raw data using {@link android.content.res.AssetManager}. For example, this can be more useful 99 when dealing with textures for a game. However, if you only need to read raw data from a file 100 (such as a video or audio file), then you should save files into the {@code res/raw/} directory and 101 then read a stream of bytes using {@link android.content.res.Resources#openRawResource(int)}. This 102 is uncommon, but if you need direct access to original files in {@code assets/}, refer to the {@link 103 android.content.res.AssetManager} documentation.</p> 104 --> 105
