android 地图:如何长按地图? [英] android maps: How to Long Click a Map?

问题描述

如何在地图视图上长按以在地图上的那个点出现地点标记?

How do I long click on a mapview so that a place marker appears at that point on the map?

我尝试了几种方法都没有成功:

I tried a couple ways without success:

1) 在 MapvView 上使用 setOnLongClickListener 从未检测到长点击.

1) Using setOnLongClickListener on the MapvView which never detected the longclicks.

2) 我的另一个想法是扩展 MapView 以覆盖 dispatchTouchEvent .. 创建一个 GestureDetector 来响应 longpress 回调.但是我被困在这里，因为我无法处理我的子类 Mapview.即

2) My other idea was to extend MapView to override dispatchTouchEvent .. Create a GestureDetector to respond to longpress callback. But I was stuck midway here as I could not get a handle to my subclassed Mapview. i.e.

MyMapview mymapview; //MyMapView extends MapView

//results in a classcast exception
mymapView = (MyMapView) findViewById(R.id.map);

3) 我知道如何尝试的唯一其他方法是:检测 MotionEvent.ACTION_DOWN 并将延迟的 runnable 发布到处理程序，如果其他两个事件:acton_move 或 action_up 未发生，则检测长按.

3) The only other way I know how to try this is: Detect a MotionEvent.ACTION_DOWN and post a delayed runnable to a handler and detect longpress if the two other events: acton_move or an action_up, have not happened.

有人可以提供有关这些检测长按的方法的想法吗?

Can someone provide thoughts on any of these methods to detect long presses?

推荐答案

我找到了更简单的方法.只需将叠加层作为列表中不绘制任何内容的第一个叠加层，并使用它来识别使用 GestureDetector 的手势.如果它处理了事件，那么它应该返回 true，这样它就不会被传播.

I've found an even easier way. Just make an overlay as the first overlay in the list that does not draw anything and use it to recognize gestures using the GestureDetector. It should then return true if it handled the event so it doesn't get propagated.

    List<Overlay> overlays = mapView.getOverlays();
    overlays.clear();
    overlays.add(new MapGestureDetectorOverlay(new MyOnGestureListener()));

这是课程:

public class MapGestureDetectorOverlay extends Overlay implements OnGestureListener {
 private GestureDetector gestureDetector;
 private OnGestureListener onGestureListener;

 public MapGestureDetectorOverlay() {
  gestureDetector = new GestureDetector(this);
 }

 public MapGestureDetectorOverlay(OnGestureListener onGestureListener) {
  this();
  setOnGestureListener(onGestureListener);
 }

 @Override
 public boolean onTouchEvent(MotionEvent event, MapView mapView) {
  if (gestureDetector.onTouchEvent(event)) {
   return true;
  }
  return false;
 }

 @Override
 public boolean onDown(MotionEvent e) {
  if (onGestureListener != null) {
   return onGestureListener.onDown(e);
  }
  return false;
 }

 @Override
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
   float velocityY) {
  if (onGestureListener != null) {
   return onGestureListener.onFling(e1, e2, velocityX, velocityY);
  }
  return false;
 }

 @Override
 public void onLongPress(MotionEvent e) {
  if (onGestureListener != null) {
   onGestureListener.onLongPress(e);
  }
 }

 @Override
 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
   float distanceY) {
  if (onGestureListener != null) {
   onGestureListener.onScroll(e1, e2, distanceX, distanceY);
  }
  return false;
 }

 @Override
 public void onShowPress(MotionEvent e) {
  if (onGestureListener != null) {
   onGestureListener.onShowPress(e);
  }
 }

 @Override
 public boolean onSingleTapUp(MotionEvent e) {
  if (onGestureListener != null) {
   onGestureListener.onSingleTapUp(e);
  }
  return false;
 }

 public boolean isLongpressEnabled() {
  return gestureDetector.isLongpressEnabled();
 }

 public void setIsLongpressEnabled(boolean isLongpressEnabled) {
  gestureDetector.setIsLongpressEnabled(isLongpressEnabled);
 }

 public OnGestureListener getOnGestureListener() {
  return onGestureListener;
 }

 public void setOnGestureListener(OnGestureListener onGestureListener) {
  this.onGestureListener = onGestureListener;
 }
}

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