1 page.title=Resources Overview 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 compatibility with different configurations, you must organize resources in your 28 project's {@code res/} directory, using various sub-directories that group resources by type and 29 configuration.</p> 30 31 <div class="figure" style="width:429px"> 32 <img src="{@docRoot}images/resources/resource_devices_diagram1.png" height="167" alt="" /> 33 <p class="img-caption"> 34 <strong>Figure 1.</strong> Two different devices, each using the default layout 35 (the app provides no alternative layouts).</p> 36 </div> 37 38 <div class="figure" style="width:429px"> 39 <img src="{@docRoot}images/resources/resource_devices_diagram2.png" height="167" alt="" /> 40 <p class="img-caption"> 41 <strong>Figure 2.</strong> Two different devices, each using a different layout provided 42 for different screen sizes.</p> 43 </div> 44 45 <p>For any type of resource, you can specify <em>default</em> and multiple 46 <em>alternative</em> resources for your application:</p> 47 <ul> 48 <li>Default resources are those that should be used regardless of 49 the device configuration or when there are no alternative resources that match the current 50 configuration.</li> 51 <li>Alternative resources are those that you've designed for use with a specific 52 configuration. To specify that a group of resources are for a specific configuration, 53 append an appropriate configuration qualifier to the directory name.</li> 54 </ul> 55 56 <p>For example, while your default UI 57 layout is saved in the {@code res/layout/} directory, you might specify a different layout to 58 be used when the screen is in landscape orientation, by saving it in the {@code res/layout-land/} 59 directory. Android automatically applies the appropriate resources by matching the 60 device's current configuration to your resource directory names.</p> 61 62 <p>Figure 1 illustrates how the system applies the same layout for 63 two different devices when there are no alternative resources available. Figure 2 shows 64 the same application when it adds an alternative layout resource for larger screens.</p> 65 66 <p>The following documents provide a complete guide to how you can organize your application resources, 67 specify alternative resources, access them in your application, and more:</p> 68 69 <dl> 70 <dt><strong><a href="providing-resources.html">Providing Resources</a></strong></dt> 71 <dd>What kinds of resources you can provide in your app, where to save them, and how to create 72 alternative resources for specific device configurations.</dd> 73 <dt><strong><a href="accessing-resources.html">Accessing Resources</a></strong></dt> 74 <dd>How to use the resources you've provided, either by referencing them from your application 75 code or from other XML resources.</dd> 76 <dt><strong><a href="runtime-changes.html">Handling Runtime Changes</a></strong></dt> 77 <dd>How to manage configuration changes that occur while your Activity is running.</dd> 78 <dt><strong><a href="localization.html">Localization</a></strong></dt> 79 <dd>A bottom-up guide to localizing your application using alternative resources. While this is 80 just one specific use of alternative resources, it is very important in order to reach more 81 users.</dd> 82 <dt><strong><a href="available-resources.html">Resource Types</a></strong></dt> 83 <dd>A reference of various resource types you can provide, describing their XML elements, 84 attributes, and syntax. For example, this reference shows you how to create a resource for 85 application menus, drawables, animations, and more.</dd> 86 </dl> 87 88 <!-- 89 <h2>Raw Assets</h2> 90 91 <p>An alternative to saving files in {@code res/} is to save files in the {@code 92 assets/} directory. This should only be necessary if you need direct access to original files and 93 directories by name. Files saved in the {@code assets/} directory will not be given a resource 94 ID, so you can't reference them through the {@code R} class or from XML resources. Instead, you can 95 query data in the {@code assets/} directory like an ordinary file system, search through the 96 directory and 97 read raw data using {@link android.content.res.AssetManager}. For example, this can be more useful 98 when dealing with textures for a game. However, if you only need to read raw data from a file 99 (such as a video or audio file), then you should save files into the {@code res/raw/} directory and 100 then read a stream of bytes using {@link android.content.res.Resources#openRawResource(int)}. This 101 is uncommon, but if you need direct access to original files in {@code assets/}, refer to the {@link 102 android.content.res.AssetManager} documentation.</p> 103 --> 104
