Setting "task affinity" programmatically

You cannot.

taskAffinity is contained by ActivityInfo, which is member of Activity.

Source code of Activity

public class Activity extends ContextThemeWrapper    ...    ... {    // set by the thread after the constructor and before     // onCreate(Bundle savedInstanceState) is called.    @UnsupportedAppUsage    /*package*/ ActivityInfo mActivityInfo; }

And ActivityInfo has taskAffinity.

Source code of ActivityInfo

/** * Information you can retrieve about a particular application * activity or receiver. This corresponds to information collected * from the AndroidManifest.xml's <activity> and * <receiver> tags. */public class ActivityInfo extends ComponentInfo implements Parcelable {   /**    * The affinity this activity has for another task in the system.  The    * string here is the name of the task, often the package name of the    * overall package.  If null, the activity has no affinity.  Set from the    * {@link android.R.attr#taskAffinity} attribute.    */    public String taskAffinity;

According to the comment of source code, information of taskAffinity is collected from AndroidManifest.xml. And there is no public method to set mActivityInfo.taskAffinity.

Use this method :

finishAffinity();