Android地图获取滚动事件

Question

我目前正在开发一个带Andoid Maps SDK的应用程序。

现在我想获得一个通知，如果用户滚动地图从基于新地图中心的服务器加载额外的标记。

我已经搜索了一个函数来注册一个监听器，但是我没有找到任何东西。

有什么方法可以获得关于地图中心更改的信息吗？我不希望实现为轮询机制... :(

Answer 1

我已经在两个方面做到了这一点：。

触摸听者设置触摸侦听器地图视图每次用户提起他们的手指（或移动，或触地），你可以重新加载。

mapView.setOnTouchListener(new OnTouchListener() { 

    public boolean onTouch(View v, MotionEvent event) { 
     switch (event.getAction()) { 
     case MotionEvent.ACTION_UP: 
      // The user took their finger off the map, 
      // they probably just moved it to a new place. 
      break; 
      case MotionEvent.ACTION_MOVE: 
      // The user is probably moving the map. 
      break; 
     } 

     // Return false so that the map still moves. 
     return false; 
    } 
}); 

覆盖onLayout。每次地图上移动，onLayout被调用。如果扩展MapView类，则可以覆盖onLayout来捕捉这些事件。我在这里设置了一个计时器来查看movem是否正确ent已经停止。

public class ExtendedMapView extends MapView { 
    private static final long STOP_TIMER_DELAY = 1500; // 1.5 seconds 
    private ScheduledThreadPoolExecutor mExecutor; 
    private OnMoveListener mOnMoveListener; 
    private Future mStoppedMovingFuture; 

    /** 
    * Creates a new extended map view. 
    * Make sure to override the other constructors if you plan to use them. 
    */ 
    public ExtendedMapView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     mExecutor = new ScheduledThreadPoolExecutor(1); 
    } 

    public interface OnMoveListener { 
     /** 
     * Notifies that the map has moved. 
     * If the map is moving, this will be called frequently, so don't spend 
     * too much time in this function. If the stopped variable is true, 
     * then the map has stopped moving. This may be useful if you want to 
     * refresh the map when the map moves, but not with every little movement. 
     * 
     * @param mapView the map that moved 
     * @param center the new center of the map 
     * @param stopped true if the map is no longer moving 
     */ 
     public void onMove(MapView mapView, GeoPoint center, boolean stopped); 
    } 

    @Override 
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 
     super.onLayout(changed, left, top, right, bottom); 

     if (mOnMoveListener != null) { 
      // Inform the listener that the map has moved. 
      mOnMoveListener.onMove(this, getMapCenter(), false); 

      // We also want to notify the listener when the map stops moving. 
      // Every time the map moves, reset the timer. If the timer ever completes, 
      // then we know that the map has stopped moving. 
      if (mStoppedMovingFuture != null) { 
       mStoppedMovingFuture.cancel(false); 
      } 
      mStoppedMovingFuture = mExecutor.schedule(onMoveStop, STOP_TIMER_DELAY, 
        TimeUnit.MILLISECONDS); 
     } 
    } 

    /** 
    * This is run when we have stopped moving the map. 
    */ 
    private Runnable onMoveStop = new Runnable() { 
     public void run() { 
      if (mOnMoveListener != null) { 
       mOnMoveListener.onMove(ExtendedMapView.this, getMapCenter(), true); 
      } 
     } 
    }; 
} 

您也可以在触摸侦听器方法中使用该定时器。这只是一个例子。我希望这有帮助！

Answer 2

看看下面的博客文章（自带Github的代码）： http://bricolsoftconsulting.com/extending-mapview-to-add-a-change-event/