管理Android版本：每个版本使用不同的类

Question

I am using this class from my main activity:

public class MediaInfo {
    public String name;
    public String label;
    // ... (other String and int fields)
    public MediaSession mSession;
}

within an ArrayList:

public class MainActivity extends ActionBarActivity implements AsyncResponse {

    private static final String TAG = "MainActivity";

    ArrayList<MediaInfo> myMediaList;
    private Context mContext;

    public void onCreate(Bundle savedInstanceState) {
        // ...
    }

    // ...
}

The problem I have is that MediaSession is a class that belongs to Android API version 21, and I am trying to make an app from version 14 on.

I would like the activity (or the class) to ignore the field containing the MediaSession class when the version is < 21. The first idea I have come across is using an abstract class and extend it when the version is >= 21, but then I would have to declare different ArrayLists, and I am not sure how I could do it. And maybe this is not the best way...

Any ideas...?

Thank you for your advice

Answer 1

The problem I have is that MediaSession is a class that belongs to Android API version 21, and I am trying to make an app from version 14 on.

Looking at the Android support library , it seems there is a backward compatible version of MediaSession, called MediaSessionCompat .

Answer 2

user3829751's answer looks good for this case.

For this generic problem I would lead you to this question: Programmatically obtain the Android API level of a device?

Also check the @TargetApi annotation. You can extract your "version-21" to a method and call it only if the runtime if version 21. You can see an example here: https://stackoverflow.com/a/18449951/3032209