<uses-sdk android:minSdkVersion="integer" android:targetSdkVersion="integer" android:maxSdkVersion="integer" />
<manifest>
Despite its name, this element is used to specify the API Level, not the version number of the SDK (software development kit) or Android platform. The API Level is always a single integer. You cannot derive the API Level from its associated Android version number (for example, it is not the same as the major version or the sum of the major and minor versions).
For more information, read about Android API Levels and Versioning Your Applications.
Android Market and <uses-sdk> attributes
Android Market filters the applications that are visible to users, so
that users can only see and download applications that are compatible with their
devices. One of the ways Market filters applications is by Android
version-compatibility. To do this, Market checks the <uses-sdk>
attributes in each application's manifest to establish its version-compatibility
range, then shows or hides the application based on a comparison with the API
Level of the user's Android system version. For more information, see Market Filters.
android:minSdkVersion
Caution: If you do not declare this
attribute, the system assumes a default value of "1", which indicates that your
application is compatible with all versions of Android. If your application is
not compatible with all versions (for instance, it uses APIs introduced
in API Level 3) and you have not declared the proper android:minSdkVersion
,
then when installed on a system with an API Level less than 3, the application
will crash during runtime when attempting to access the unavailable APIs. For
this reason, be certain to declare the appropriate API Level in the
minSdkVersion
attribute.
android:targetSdkVersion
With this attribute set, the application says that it is able to run on
older versions (down to minSdkVersion
), but was explicitly tested to
work with the version specified here. Specifying this target version allows the
platform to disable compatibility settings that are not required for the target
version (which may otherwise be turned on in order to maintain
forward-compatibility) or enable newer features that are not available to older
applications. This does not mean that you can program different features for
different versions of the platform—it simply informs the platform that you
have tested against the target version and the platform should not perform any
extra work to maintain forward-compatibility with the target version.
Introduced in: API Level 4
android:maxSdkVersion
In Android 1.5, 1.6, 2.0, and 2.0.1, the system checks the value of this
attribute when installing an application and when revalidating the application
after a system update. In either case, if the application's
android:maxSdkVersion
attribute is lower than the API Level used by
the system itself, then the system will not allow the application to be
installed. In the case of revalidation after system update, this effectively
removes your application from the device.
To illustrate how this attribute can affect your application after system updates, consider the following example:
An application declaring android:maxSdkVersion="5"
in its
manifest is published on Android Market. A user whose device is running Android
1.6 (API Level 4) downloads and installs the app. After a few weeks, the user
receives an over-the-air system update to Android 2.0 (API Level 5). After the
update is installed, the system checks the application's
android:maxSdkVersion
and successfully revalidates it. The
application functions as normal. However, some time later, the device receives
another system update, this time to Android 2.0.1 (API Level 6). After the
update, the system can no longer revalidate the application because the system's
own API Level (6) is now higher than the maximum supported by the application
(5). The system prevents the application from being visible to the user, in
effect removing it from the device.
Warning: Declaring this attribute is not recommended. First, there is no need to set the attribute as means of blocking deployment of your application onto new versions of the Android platform as they are released. By design, new versions of the platform are fully backward-compatible. Your application should work properly on new versions, provided it uses only standard APIs and follows development best practices. Second, note that in some cases, declaring the attribute can result in your application being removed from users' devices after a system update to a higher API Level. Most devices on which your appplication is likely to be installed will receive periodic system updates over the air, so you should consider their effect on your application before setting this attribute.
Introduced in: API Level 4
android:maxSdkVersion
attribute during
installation or revalidation. Android Market will continue to use the attribute
as a filter, however, when presenting users with applications available for
download.