public class HoverDemoActivity extends Activity {  private Button btnBottom;  @Override  public void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main);    btnBottom = (Button) findViewById(R.id.btn_bottom);    btnBottom.setOnHoverListener(new OnHoverListener() {      @Override      public boolean onHover(View v, MotionEvent event) {        int what = event.getAction();        switch(what){         case MotionEvent.ACTION_HOVER_ENTER: //鼠標進入view           System.out.println("bottom ACTION_HOVER_ENTER");           break;         case MotionEvent.ACTION_HOVER_MOVE: //鼠標在view上           System.out.println("bottom ACTION_HOVER_MOVE");           break;         case MotionEvent.ACTION_HOVER_EXIT: //鼠標離開view           System.out.println("bottom ACTION_HOVER_EXIT");           break;        }        return false;      }    });  }}