1 page.title=<uses-sdk> 2 parent.title=The AndroidManifest.xml File 3 parent.link=manifest-intro.html 4 @jd:body 5 6 7 <div id="qv-wrapper"> 8 <div id="qv"> 9 10 <h2>In this document</h2> 11 <ol> 12 <li><a href="#ApiLevels">What is API Level?</a></li> 13 <li><a href="#uses">Uses of API Level in Android</a></li> 14 <li><a href="#considerations">Development Considerations</a> 15 <ol> 16 <li><a href="#fc">Application forward compatibility</a></li> 17 <li><a href="#bc">Application backward compatibility</a></li> 18 <li><a href="#platform">Selecting a platform version and API Level</a></li> 19 <li><a href="#apilevel">Declaring a minimum API Level</a></li> 20 <li><a href="#testing">Testing against higher API Levels</a></li> 21 </ol> 22 </li> 23 <li><a href="#provisional">Using a Provisional API Level</a></li> 24 <li><a href="#filtering">Filtering the Reference Documentation by API Level</a></li> 25 </ol> 26 </div> 27 </div> 28 29 <dl class="xml"> 30 <dt>syntax:</dt> 31 <dd><pre> 32 <uses-sdk android:<a href="#min">minSdkVersion</a>="<i>integer</i>" 33 android:<a href="#target">targetSdkVersion</a>="<i>integer</i>" 34 android:<a href="#max">maxSdkVersion</a>="<i>integer</i>" /></pre></dd> 35 36 <dt>contained in:</dt> 37 <dd><code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code></dd> 38 39 <dt>description:</dt> 40 <dd>Lets you express an application's compatibility with one or more versions of the Android platform, 41 by means of an API Level integer. The API Level expressed by an application will be compared to the 42 API Level of a given Android system, which may vary among different Android devices. 43 </p> 44 45 <p>Despite its name, this element is used to specify the API Level, <em>not</em> 46 the version number of the SDK (software development kit) or Android platform. 47 The API Level is always a single integer. You cannot derive the API Level from 48 its associated Android version number (for example, it is not the same as the 49 major version or the sum of the major and minor versions).</p> 50 51 <p>Also read the document about 52 <a href="{@docRoot}tools/publishing/versioning.html">Versioning Your Applications</a>. 53 </p></dd> 54 55 <div class="sidebox-wrapper" xstyle="margin-bottom:2em;margin-top:.5em;width:90%;"> 56 <img id="rule" src="{@docRoot}assets/images/grad-rule-qv.png"> 57 <div id="qv-sub-rule"> 58 <img src="{@docRoot}assets/images/icon_play.png" style="float:left;margin:0;padding:0;"> 59 <p style="color:#669999;padding-top:1em;">Google Play and <uses-sdk> attributes</p> 60 <p style="padding-top:1em;">Google Play filters the applications that are visible to users, so 61 that users can only see and download applications that are compatible with their 62 devices. One of the ways it filters applications is by Android 63 version-compatibility. To do this, Google Play checks the <code><uses-sdk></code> 64 attributes in each application's manifest to establish its version-compatibility 65 range, then shows or hides the application based on a comparison with the API 66 Level of the user's Android system version. For more information, see <a 67 href="{@docRoot}guide/google/play/filters.html">Filters on Google Play</a>.</p> 68 </div> 69 </div> 70 71 <dt>attributes:</dt> 72 73 <dd> 74 <dl class="attr"> 75 <dt><a name="min"></a>{@code android:minSdkVersion}</dt> 76 <dd>An integer designating the minimum API Level required 77 for the application to run. The Android system will prevent the user from installing 78 the application if the system's API Level is lower than the value specified in 79 this attribute. You should always declare this attribute. 80 81 <p class="caution"><strong>Caution:</strong> If you do not declare this 82 attribute, the system assumes a default value of "1", which indicates that your 83 application is compatible with all versions of Android. If your application is 84 <em>not</em> compatible with all versions (for instance, it uses APIs introduced 85 in API Level 3) and you have not declared the proper <code>minSdkVersion</code>, 86 then when installed on a system with an API Level less than 3, the application 87 will crash during runtime when attempting to access the unavailable APIs. For 88 this reason, be certain to declare the appropriate API Level in the 89 <code>minSdkVersion</code> attribute.</p> 90 </dd> 91 92 <dt><a name="target"></a>{@code android:targetSdkVersion}</dt> 93 <dd>An integer designating the API Level that the application targets. If not set, the default 94 value equals that given to {@code minSdkVersion}. 95 96 <p>This attribute informs the system that you have tested against the target version and the 97 system should not enable any compatibility behaviors to maintain your app's forward-compatibility 98 with the target version. The application is still able to run on older versions (down to {@code 99 minSdkVersion}).</p> 100 101 <p>As Android evolves with each new version, some behaviors and even appearances might change. 102 However, if the API level of the platform is higher than the version declared by your app's {@code 103 targetSdkVersion}, the system may enable compatibility behaviors to ensure that your app 104 continues to work the way you expect. You can disable such compatibility 105 behaviors by specifying {@code targetSdkVersion} to match the API 106 level of the platform on which it's running. For example, setting this value to "11" or higher 107 allows the system to apply a new default theme (Holo) to your app when running on Android 3.0 or 108 higher and also disables <a href="{@docRoot}guide/practices/screen-compat-mode.html">screen 109 compatibility mode</a> when running on larger screens (because support for API level 11 implicitly 110 supports larger screens).</p> 111 112 <p>There are many compatibility behaviors that the system may enable based on the value you set 113 for this attribute. Several of these behaviors are described by the corresponding platform versions 114 in the {@link android.os.Build.VERSION_CODES} reference.</p> 115 116 <p>To maintain your application along with each Android release, you should increase 117 the value of this attribute to match the latest API level, then thoroughly test your application on 118 the corresponding platform version.</p> 119 120 <p>Introduced in: API Level 4</p> 121 </dd> 122 123 <dt><a name="max"></a>{@code android:maxSdkVersion}</dt> 124 <dd>An integer designating the maximum API Level on which the application is 125 designed to run. 126 127 <p>In Android 1.5, 1.6, 2.0, and 2.0.1, the system checks the value of this 128 attribute when installing an application and when re-validating the application 129 after a system update. In either case, if the application's 130 <code>maxSdkVersion</code> attribute is lower than the API Level used by 131 the system itself, then the system will not allow the application to be 132 installed. In the case of re-validation after system update, this effectively 133 removes your application from the device. 134 135 <p>To illustrate how this attribute can affect your application after system 136 updates, consider the following example: </p> 137 138 <p>An application declaring <code>maxSdkVersion="5"</code> in its 139 manifest is published on Google Play. A user whose device is running Android 140 1.6 (API Level 4) downloads and installs the app. After a few weeks, the user 141 receives an over-the-air system update to Android 2.0 (API Level 5). After the 142 update is installed, the system checks the application's 143 <code>maxSdkVersion</code> and successfully re-validates it. The 144 application functions as normal. However, some time later, the device receives 145 another system update, this time to Android 2.0.1 (API Level 6). After the 146 update, the system can no longer re-validate the application because the system's 147 own API Level (6) is now higher than the maximum supported by the application 148 (5). The system prevents the application from being visible to the user, in 149 effect removing it from the device.</p> 150 151 <p class="warning"><strong>Warning:</strong> Declaring this attribute is not 152 recommended. First, there is no need to set the attribute as means of blocking 153 deployment of your application onto new versions of the Android platform as they 154 are released. By design, new versions of the platform are fully 155 backward-compatible. Your application should work properly on new versions, 156 provided it uses only standard APIs and follows development best practices. 157 Second, note that in some cases, declaring the attribute can <strong>result in 158 your application being removed from users' devices after a system 159 update</strong> to a higher API Level. Most devices on which your application 160 is likely to be installed will receive periodic system updates over the air, so 161 you should consider their effect on your application before setting this 162 attribute.</p> 163 164 <p style="margin-bottom:1em;">Introduced in: API Level 4</p> 165 166 <div class="special">Future versions of Android (beyond Android 2.0.1) will no 167 longer check or enforce the <code>maxSdkVersion</code> attribute during 168 installation or re-validation. Google Play will continue to use the attribute 169 as a filter, however, when presenting users with applications available for 170 download. </div> 171 </dd> 172 173 174 </dl></dd> 175 176 <!-- ##api level indication## --> 177 <dt>introduced in:</dt> 178 <dd>API Level 1</dd> 179 180 </dl> 181 182 183 184 185 186 <!--- CONTENT FROM OLD API LEVEL DOC ----> 187 188 189 190 191 <h2 id="ApiLevels">What is API Level?</h2> 192 193 <p>API Level is an integer value that uniquely identifies the framework API 194 revision offered by a version of the Android platform.</p> 195 196 <p>The Android platform provides a framework API that applications can use to 197 interact with the underlying Android system. The framework API consists of:</p> 198 199 <ul> 200 <li>A core set of packages and classes</li> 201 <li>A set of XML elements and attributes for declaring a manifest file</li> 202 <li>A set of XML elements and attributes for declaring and accessing resources</li> 203 <li>A set of Intents</li> 204 <li>A set of permissions that applications can request, as well as permission 205 enforcements included in the system</li> 206 </ul> 207 208 <p>Each successive version of the Android platform can include updates to the 209 Android application framework API that it delivers. </p> 210 211 <p>Updates to the framework API are designed so that the new API remains 212 compatible with earlier versions of the API. That is, most changes in the API 213 are additive and introduce new or replacement functionality. As parts of the API 214 are upgraded, the older replaced parts are deprecated but are not removed, so 215 that existing applications can still use them. In a very small number of cases, 216 parts of the API may be modified or removed, although typically such changes are 217 only needed to ensure API robustness and application or system security. All 218 other API parts from earlier revisions are carried forward without 219 modification.</p> 220 221 <p>The framework API that an Android platform delivers is specified using an 222 integer identifier called "API Level". Each Android platform version supports 223 exactly one API Level, although support is implicit for all earlier API Levels 224 (down to API Level 1). The initial release of the Android platform provided 225 API Level 1 and subsequent releases have incremented the API Level.</p> 226 227 <p>The following table specifies the API Level supported by each version of the 228 Android platform.</p> 229 230 <table> 231 <tr><th>Platform Version</th><th>API Level</th><th>VERSION_CODE</th><th>Notes</th></tr> 232 233 <tr><td><a href="{@docRoot}about/versions/android-4.1.html">Android 4.1, 4.1.1</a></td> 234 <td><a href="{@docRoot}sdk/api_diff/16/changes.html" title="Diff Report">16</a></td> 235 <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN}</td> 236 <td><a href="{@docRoot}about/versions/jelly-bean.html">Platform 237 Highlights</a></td></tr> 238 239 <tr><td><a href="{@docRoot}about/versions/android-4.0.3.html">Android 4.0.3, 4.0.4</a></td> 240 <td><a href="{@docRoot}sdk/api_diff/15/changes.html" title="Diff Report">15</a></td> 241 <td>{@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH_MR1}</td> 242 <td rowspan="2"><a href="{@docRoot}about/versions/android-4.0-highlights.html">Platform 243 Highlights</a></td></tr> 244 245 <tr><td><a href="{@docRoot}about/versions/android-4.0.html">Android 4.0, 4.0.1, 4.0.2</a></td> 246 <td><a href="{@docRoot}sdk/api_diff/14/changes.html" title="Diff Report">14</a></td> 247 <td>{@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH}</td> 248 </tr> 249 250 <tr><td><a href="{@docRoot}about/versions/android-3.2.html">Android 3.2</a></td> 251 <td><a href="{@docRoot}sdk/api_diff/13/changes.html" title="Diff Report">13</a></td> 252 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB_MR2}</td> 253 <td><!-- <a href="{@docRoot}about/versions/android-3.2-highlights.html">Platform 254 Highlights</a>--></td></tr> 255 256 <tr><td><a href="{@docRoot}about/versions/android-3.1.html">Android 3.1.x</a></td> 257 <td><a href="{@docRoot}sdk/api_diff/12/changes.html" title="Diff Report">12</a></td> 258 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB_MR1}</td> 259 <td><a href="{@docRoot}about/versions/android-3.1-highlights.html">Platform Highlights</a></td></tr> 260 261 <tr><td><a href="{@docRoot}about/versions/android-3.0.html">Android 3.0.x</td> 262 <td><a href="{@docRoot}sdk/api_diff/11/changes.html" title="Diff Report">11</a></td> 263 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB}</td> 264 <td><a href="{@docRoot}about/versions/android-3.0-highlights.html">Platform Highlights</a></td></tr> 265 266 <tr><td><a href="{@docRoot}about/versions/android-2.3.3.html">Android 2.3.4<br>Android 2.3.3</td> 267 <td><a href="{@docRoot}sdk/api_diff/10/changes.html" title="Diff Report">10</a></td> 268 <td>{@link android.os.Build.VERSION_CODES#GINGERBREAD_MR1}</td> 269 <td rowspan="2"><a href="{@docRoot}about/versions/android-2.3-highlights.html">Platform 270 Highlights</a></td></tr> 271 272 <tr><td><a href="{@docRoot}about/versions/android-2.3.html">Android 2.3.2<br>Android 2.3.1<br>Android 273 2.3</td> 274 <td><a href="{@docRoot}sdk/api_diff/9/changes.html" title="Diff Report">9</a></td> 275 <td>{@link android.os.Build.VERSION_CODES#GINGERBREAD}</td> 276 </tr> 277 278 <tr><td><a href="{@docRoot}about/versions/android-2.2.html">Android 2.2.x</td> 279 <td ><a href="{@docRoot}sdk/api_diff/8/changes.html" title="Diff Report">8</a></td> 280 <td>{@link android.os.Build.VERSION_CODES#FROYO}</td> 281 <td><a href="{@docRoot}about/versions/android-2.2-highlights.html">Platform Highlights</a></td></tr> 282 283 <tr><td><a href="{@docRoot}about/versions/android-2.1.html">Android 2.1.x</td> 284 <td><a href="{@docRoot}sdk/api_diff/7/changes.html" title="Diff Report">7</a></td> 285 <td>{@link android.os.Build.VERSION_CODES#ECLAIR_MR1}</td> 286 <td rowspan="3" ><a href="{@docRoot}about/versions/android-2.0-highlights.html">Platform 287 Highlights</a></td></tr> 288 289 <tr><td><a href="{@docRoot}about/versions/android-2.0.1.html">Android 2.0.1</td> 290 <td><a href="{@docRoot}sdk/api_diff/6/changes.html" title="Diff Report">6</a></td> 291 <td>{@link android.os.Build.VERSION_CODES#ECLAIR_0_1}</td> 292 </tr> 293 294 <tr><td><a href="{@docRoot}about/versions/android-2.0.html">Android 2.0</td> 295 <td><a href="{@docRoot}sdk/api_diff/5/changes.html" title="Diff Report">5</a></td> 296 <td>{@link android.os.Build.VERSION_CODES#ECLAIR}</td> 297 </tr> 298 299 <tr><td><a href="{@docRoot}about/versions/android-1.6.html">Android 1.6</td> 300 <td><a href="{@docRoot}sdk/api_diff/4/changes.html" title="Diff Report">4</a></td> 301 <td>{@link android.os.Build.VERSION_CODES#DONUT}</td> 302 <td><a href="{@docRoot}about/versions/android-1.6-highlights.html">Platform Highlights</a></td></tr> 303 304 <tr><td><a href="{@docRoot}about/versions/android-1.5.html">Android 1.5</td> 305 <td><a href="{@docRoot}sdk/api_diff/3/changes.html" title="Diff Report">3</a></td> 306 <td>{@link android.os.Build.VERSION_CODES#CUPCAKE}</td> 307 <td><a href="{@docRoot}about/versions/android-1.5-highlights.html">Platform Highlights</a></td></tr> 308 309 <tr><td><a href="{@docRoot}about/versions/android-1.1.html">Android 1.1</td> 310 <td>2</td> 311 <td>{@link android.os.Build.VERSION_CODES#BASE_1_1}</td><td></td></tr> 312 313 <tr><td>Android 1.0</td> 314 <td>1</td> 315 <td>{@link android.os.Build.VERSION_CODES#BASE}</td> 316 <td></td></tr> 317 </table> 318 319 320 <h2 id="uses">Uses of API Level in Android</h2> 321 322 <p>The API Level identifier serves a key role in ensuring the best possible 323 experience for users and application developers: 324 325 <ul> 326 <li>It lets the Android platform describe the maximum framework API revision 327 that it supports</li> 328 <li>It lets applications describe the framework API revision that they 329 require</li> 330 <li>It lets the system negotiate the installation of applications on the user's 331 device, such that version-incompatible applications are not installed.</li> 332 </ul> 333 334 <p>Each Android platform version stores its API Level identifier internally, in 335 the Android system itself. </p> 336 337 <p>Applications can use a manifest element provided by the framework API — 338 <code><uses-sdk></code> — to describe the minimum and maximum API 339 Levels under which they are able to run, as well as the preferred API Level that 340 they are designed to support. The element offers three key attributes:</p> 341 342 <ul> 343 <li><code>android:minSdkVersion</code> — Specifies the minimum API Level 344 on which the application is able to run. The default value is "1".</li> 345 <li><code>android:targetSdkVersion</code> — Specifies the API Level 346 on which the application is designed to run. In some cases, this allows the 347 application to use manifest elements or behaviors defined in the target 348 API Level, rather than being restricted to using only those defined 349 for the minimum API Level.</li> 350 <li><code>android:maxSdkVersion</code> — Specifies the maximum API Level 351 on which the application is able to run. <strong>Important:</strong> Please read the <a 352 href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 353 documentation before using this attribute. </li> 354 </ul> 355 356 <p>For example, to specify the minimum system API Level that an application 357 requires in order to run, the application would include in its manifest a 358 <code><uses-sdk></code> element with a <code>android:minSdkVersion</code> 359 attribute. The value of <code>android:minSdkVersion</code> would be the integer 360 corresponding to the API Level of the earliest version of the Android platform 361 under which the application can run. </p> 362 363 <p>When the user attempts to install an application, or when revalidating an 364 appplication after a system update, the Android system first checks the 365 <code><uses-sdk></code> attributes in the application's manifest and 366 compares the values against its own internal API Level. The system allows the 367 installation to begin only if these conditions are met:</p> 368 369 <ul> 370 <li>If a <code>android:minSdkVersion</code> attribute is declared, its value 371 must be less than or equal to the system's API Level integer. If not declared, 372 the system assumes that the application requires API Level 1. </li> 373 <li>If a <code>android:maxSdkVersion</code> attribute is declared, its value 374 must be equal to or greater than the system's API Level integer. 375 If not declared, the system assumes that the application 376 has no maximum API Level. Please read the <a 377 href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 378 documentation for more information about how the system handles this attribute.</li> 379 </ul> 380 381 <p>When declared in an application's manifest, a <code><uses-sdk></code> 382 element might look like this: </p> 383 384 <pre><manifest> 385 <uses-sdk android:minSdkVersion="5" /> 386 ... 387 </manifest></pre> 388 389 <p>The principal reason that an application would declare an API Level in 390 <code>android:minSdkVersion</code> is to tell the Android system that it is 391 using APIs that were <em>introduced</em> in the API Level specified. If the 392 application were to be somehow installed on a platform with a lower API Level, 393 then it would crash at run-time when it tried to access APIs that don't exist. 394 The system prevents such an outcome by not allowing the application to be 395 installed if the lowest API Level it requires is higher than that of the 396 platform version on the target device.</p> 397 398 <p>For example, the {@link android.appwidget} package was introduced with API 399 Level 3. If an application uses that API, it must declare a 400 <code>android:minSdkVersion</code> attribute with a value of "3". The 401 application will then be installable on platforms such as Android 1.5 (API Level 402 3) and Android 1.6 (API Level 4), but not on the Android 1.1 (API Level 2) and 403 Android 1.0 platforms (API Level 1).</p> 404 405 <p>For more information about how to specify an application's API Level 406 requirements, see the <a 407 href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 408 section of the manifest file documentation.</p> 409 410 411 <h2 id="considerations">Development Considerations</h2> 412 413 <p>The sections below provide information related to API level that you should 414 consider when developing your application.</p> 415 416 <h3 id="fc">Application forward compatibility</h3> 417 418 <p>Android applications are generally forward-compatible with new versions of 419 the Android platform.</p> 420 421 <p>Because almost all changes to the framework API are additive, an Android 422 application developed using any given version of the API (as specified by its 423 API Level) is forward-compatible with later versions of the Android platform and 424 higher API levels. The application should be able to run on all later versions 425 of the Android platform, except in isolated cases where the application uses a 426 part of the API that is later removed for some reason. </p> 427 428 <p>Forward compatibility is important because many Android-powered devices 429 receive over-the-air (OTA) system updates. The user may install your 430 application and use it successfully, then later receive an OTA update to a new 431 version of the Android platform. Once the update is installed, your application 432 will run in a new run-time version of the environment, but one that has the API 433 and system capabilities that your application depends on. </p> 434 435 <p>In some cases, changes <em>below</em> the API, such those in the underlying 436 system itself, may affect your application when it is run in the new 437 environment. For that reason it's important for you, as the application 438 developer, to understand how the application will look and behave in each system 439 environment. To help you test your application on various versions of the Android 440 platform, the Android SDK includes multiple platforms that you can download. 441 Each platform includes a compatible system image that you can run in an AVD, to 442 test your application. </p> 443 444 <h3 id="bc">Application backward compatibility</h3> 445 446 <p>Android applications are not necessarily backward compatible with versions of 447 the Android platform older than the version against which they were compiled. 448 </p> 449 450 <p>Each new version of the Android platform can include new framework APIs, such 451 as those that give applications access to new platform capabilities or replace 452 existing API parts. The new APIs are accessible to applications when running on 453 the new platform and, as mentioned above, also when running on later versions of 454 the platform, as specified by API Level. Conversely, because earlier versions of 455 the platform do not include the new APIs, applications that use the new APIs are 456 unable to run on those platforms.</p> 457 458 <p>Although it's unlikely that an Android-powered device would be downgraded to 459 a previous version of the platform, it's important to realize that there are 460 likely to be many devices in the field that run earlier versions of the 461 platform. Even among devices that receive OTA updates, some might lag and 462 might not receive an update for a significant amount of time. </p> 463 464 <h3 id="platform">Selecting a platform version and API Level</h3> 465 466 <p>When you are developing your application, you will need to choose 467 the platform version against which you will compile the application. In 468 general, you should compile your application against the lowest possible 469 version of the platform that your application can support. 470 471 <p>You can determine the lowest possible platform version by compiling the 472 application against successively lower build targets. After you determine the 473 lowest version, you should create an AVD using the corresponding platform 474 version (and API Level) and fully test your application. Make sure to declare a 475 <code>android:minSdkVersion</code> attribute in the application's manifest and 476 set its value to the API Level of the platform version. </p> 477 478 <h3 id="apilevel">Declaring a minimum API Level</h3> 479 480 <p>If you build an application that uses APIs or system features introduced in 481 the latest platform version, you should set the 482 <code>android:minSdkVersion</code> attribute to the API Level of the latest 483 platform version. This ensures that users will only be able to install your 484 application if their devices are running a compatible version of the Android 485 platform. In turn, this ensures that your application can function properly on 486 their devices. </p> 487 488 <p>If your application uses APIs introduced in the latest platform version but 489 does <em>not</em> declare a <code>android:minSdkVersion</code> attribute, then 490 it will run properly on devices running the latest version of the platform, but 491 <em>not</em> on devices running earlier versions of the platform. In the latter 492 case, the application will crash at runtime when it tries to use APIs that don't 493 exist on the earlier versions.</p> 494 495 <h3 id="testing">Testing against higher API Levels</h3> 496 497 <p>After compiling your application, you should make sure to test it on the 498 platform specified in the application's <code>android:minSdkVersion</code> 499 attribute. To do so, create an AVD that uses the platform version required by 500 your application. Additionally, to ensure forward-compatibility, you should run 501 and test the application on all platforms that use a higher API Level than that 502 used by your application. </p> 503 504 <p>The Android SDK includes multiple platform versions that you can use, 505 including the latest version, and provides an updater tool that you can use to 506 download other platform versions as necessary. </p> 507 508 <p>To access the updater, use the <code>android</code> command-line tool, 509 located in the <sdk>/tools directory. You can launch the SDK updater by 510 executing <code>android sdk</code>. You can 511 also simply double-click the android.bat (Windows) or android (OS X/Linux) file. 512 In ADT, you can also access the updater by selecting 513 <strong>Window</strong> > <strong>Android SDK 514 Manager</strong>.</p> 515 516 <p>To run your application against different platform versions in the emulator, 517 create an AVD for each platform version that you want to test. For more 518 information about AVDs, see <a 519 href="{@docRoot}tools/devices/index.html">Creating and Managing Virtual Devices</a>. If 520 you are using a physical device for testing, ensure that you know the API Level 521 of the Android platform it runs. See the table at the top of this document for 522 a list of platform versions and their API Levels. </p> 523 524 <h2 id="provisional">Using a Provisional API Level</h2> 525 526 <p>In some cases, an "Early Look" Android SDK platform may be available. To let 527 you begin developing on the platform although the APIs may not be final, the 528 platform's API Level integer will not be specified. You must instead use the 529 platform's <em>provisional API Level</em> in your application manifest, in order 530 to build applications against the platform. A provisional API Level is not an 531 integer, but a string matching the codename of the unreleased platform version. 532 The provisional API Level will be specified in the release notes for the Early 533 Look SDK release notes and is case-sensitive.</p> 534 535 <p>The use of a provisional API Level is designed to protect developers and 536 device users from inadvertently publishing or installing applications based on 537 the Early Look framework API, which may not run properly on actual devices 538 running the final system image.</p> 539 540 <p>The provisional API Level will only be valid while using the Early Look SDK 541 and can only be used to run applications in the emulator. An application using 542 the provisional API Level can never be installed on an Android device. At the 543 final release of the platform, you must replace any instances of the provisional 544 API Level in your application manifest with the final platform's actual API 545 Level integer.</p> 546 547 548 <h2 id="filtering">Filtering the Reference Documentation by API Level</h2> 549 550 <p>Reference documentation pages on the Android Developers site offer a "Filter 551 by API Level" control in the top-right area of each page. You can use the 552 control to show documentation only for parts of the API that are actually 553 accessible to your application, based on the API Level that it specifies in 554 the <code>android:minSdkVersion</code> attribute of its manifest file. </p> 555 556 <p>To use filtering, select the checkbox to enable filtering, just below the 557 page search box. Then set the "Filter by API Level" control to the same API 558 Level as specified by your application. Notice that APIs introduced in a later 559 API Level are then grayed out and their content is masked, since they would not 560 be accessible to your application. </p> 561 562 <p>Filtering by API Level in the documentation does not provide a view 563 of what is new or introduced in each API Level — it simply provides a way 564 to view the entire API associated with a given API Level, while excluding API 565 elements introduced in later API Levels.</p> 566 567 <p>If you decide that you don't want to filter the API documentation, just 568 disable the feature using the checkbox. By default, API Level filtering is 569 disabled, so that you can view the full framework API, regardless of API Level. 570 </p> 571 572 <p>Also note that the reference documentation for individual API elements 573 specifies the API Level at which each element was introduced. The API Level 574 for packages and classes is specified as "Since <api level>" at the 575 top-right corner of the content area on each documentation page. The API Level 576 for class members is specified in their detailed description headers, 577 at the right margin. </p> 578 579 580 581 582 583 584 585 586 587