如何檢測Android MapView是否已被平移或縮放？

Question

我正在創建一個基於MapView可見區域搜索項目的Android應用程序。有沒有辦法在我的MapView上設置偵聽器來檢測地圖是否被平移或縮放？

Answer 1

我能想到的唯一方法是擴展MapView並覆蓋OnTouchEvent並觀察Up操作。這會告訴你用戶已經完成移動，你可以得到經緯度來確定你應該簽出的區域。

Answer 2

試MapView的疊加經理，這是一個擴展覆蓋層爲Android地圖，

它有一些簡化OnGestureListener，幾個例子：

onSingleTap(MotionEvent, ManagedOverlay, GeoPoint, OverlayItem) 

onDoubleTap(MotionEvent, ManagedOverlay, GeoPoint, OverlayItem) 

onLongPress(MotionEvent, ManagedOverlay, GeoPoint, OverlayItem) 

onZoom(ZoomEvent, ManagedOverlay) 

onScrolled(...) 

鏈接：http://code.google.com/p/mapview-overlay-manager/希望它有助於

Answer 3

不幸的是，在MapView工具中沒有內置的功能（這是一個奇怪的疏忽，因爲這個功能在JavaScript SDK以及iOS SDK中）。

雖然使用Runnable並且只是輪詢MapView，但您可以輕鬆應對。我通過跟蹤「最後」狀態來執行此操作：

getLatitudeSpan(); 
getLongitudeSpan(); 
getCenter(); 
getZoomLevel(); 

然後將它們與當前值進行比較。如果值已更改，則知道地圖視圖已移動。如果沒有，你什麼都不能做。

無論採用哪種方式，在500ms左右之後重新安排另一次運行的runnable並重復此過程。您可以使用onResume（）和onPause（）來刪除Runnable的回調，並根據需要重新啓動它。

Answer 4

MapView類可以使用onLayout方法跟蹤更改。

即

class CustomMapView extends MapView { 

    protected void onLayout(boolean changed,int left, int right, int top, int bottom){ 
     super.onLayout(changed,left, right, top, bottom); 
     if(changed){ 
     // do something special 
     } 
    } 
} 

Answer 5

您可以創建擴展MapView的一個SimpleMapView。

public class SimpleMapView extends MapView { 

    private int currentZoomLevel = -1; 
    private GeoPoint currentCenter; 
    private List<ZoomChangeListener> zoomEvents = new ArrayList<ZoomChangeListener>(); 
    private List<PanChangeListener> panEvents = new ArrayList<PanChangeListener>(); 

    public SimpleMapView(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
    } 

    public SimpleMapView(Context context, String apiKey) { 
     super(context, apiKey); 
    } 

    public SimpleMapView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
    } 
    /** 
    * 
    * @return 
    */ 
    public int[][] getBounds() { 

     GeoPoint center = getMapCenter(); 
     int latitudeSpan = getLatitudeSpan(); 
     int longtitudeSpan = getLongitudeSpan(); 
     int[][] bounds = new int[2][2]; 

     bounds[0][0] = center.getLatitudeE6() - (latitudeSpan/2); 
     bounds[0][1] = center.getLongitudeE6() - (longtitudeSpan/2); 

     bounds[1][0] = center.getLatitudeE6() + (latitudeSpan/2); 
     bounds[1][1] = center.getLongitudeE6() + (longtitudeSpan/2); 
     return bounds; 
    } 

    public boolean onTouchEvent(MotionEvent ev) { 
     if (ev.getAction() == MotionEvent.ACTION_UP) { 
      GeoPoint centerGeoPoint = this.getMapCenter(); 
      if (currentCenter == null || 
        (currentCenter.getLatitudeE6() != centerGeoPoint.getLatitudeE6()) || 
        (currentCenter.getLongitudeE6() != centerGeoPoint.getLongitudeE6())) { 
       firePanEvent(currentCenter, this.getMapCenter()); 
      } 
      currentCenter = this.getMapCenter(); 
     } 
     return super.onTouchEvent(ev); 
    } 

    @Override 
    protected void dispatchDraw(Canvas canvas) { 
     super.dispatchDraw(canvas); 
     if(getZoomLevel() != currentZoomLevel){ 
      fireZoomLevel(currentZoomLevel, getZoomLevel()); 
      currentZoomLevel = getZoomLevel(); 
     } 
    } 

    @Override 
    public void setSatellite(boolean on){ 
     super.setSatellite(on); 
    } 

    @Override 
    public MapController getController(){ 
     return super.getController(); 
    } 

    private void fireZoomLevel(int old, int current){ 
     for(ZoomChangeListener event : zoomEvents){ 
      event.onZoom(old, current); 
     } 
    } 

    private void firePanEvent(GeoPoint old, GeoPoint current){ 
     for(PanChangeListener event : panEvents){ 
      event.onPan(old, current); 
     } 
    } 

    public void addZoomChangeListener(ZoomChangeListener listener){ 
     this.zoomEvents.add(listener); 
    } 

    public void addPanChangeListener(PanChangeListener listener){ 
     this.panEvents.add(listener); 
    } 
} 

你有聽衆，你可以把代碼放在平移或縮放。 然後在您的xml：

<com.androidnatic.maps.SimpleMapView android:clickable="true" 
        android:layout_height="match_parent" android:id="@+id/mapView" 
        android:layout_width="match_parent" 
        android:apiKey="xxx"> 
</com.androidnatic.maps.SimpleMapView> 

然後在你的代碼，你可以指定潘監聽器：

mapView.addPanChangeListener(new PanChangeListener() { 

      @Override 
      public void onPan(GeoPoint old, GeoPoint current) { 
          //TODO 
         } 
     }); 

Answer 6

老問題，但我寫了一個類，而回叫ExMapView其觸發一個事件時，地圖區域開始變化（onRegionBeginChange）並停止變化（onRegionEndChange）。該類適用於舊版MapView，不適用於V2.0。希望它能幫助別人。

import android.content.Context; 
import android.util.AttributeSet; 
import android.view.MotionEvent; 

import com.google.android.maps.GeoPoint; 
import com.google.android.maps.MapView; 

public class ExMapView extends MapView { 
    private static final String TAG = ExMapView.class.getSimpleName(); 
    private static final int DURATION_DEFAULT = 700; 

    private OnRegionChangedListener onRegionChangedListener; 
    private GeoPoint previousMapCenter; 
    private int previousZoomLevel; 
    private int changeDuration; // This is the duration between when the user stops moving the map around and when the onRegionEndChange event fires. 
    private boolean isTouched = false; 
    private boolean regionChanging = false; 

    private Runnable onRegionEndChangeTask = new Runnable() { 
     public void run() { 
      regionChanging = false; 
      previousMapCenter = getMapCenter(); 
      previousZoomLevel = getZoomLevel(); 
      if (onRegionChangedListener != null) { 
       onRegionChangedListener.onRegionEndChange(ExMapView.this, previousMapCenter, previousZoomLevel); 
      } 
     } 
    }; 

    public ExMapView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     init(); 
    } 

    public ExMapView(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     init(); 
    } 

    public ExMapView(Context context, String apiKey) { 
     super(context, apiKey); 
     init(); 
    } 

    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
     isTouched = event.getAction() != MotionEvent.ACTION_UP; 
     return super.onTouchEvent(event); 
    } 

    @Override 
    public void computeScroll() { 
     super.computeScroll(); 

     // If the map region is still changing (user is still scrolling or zooming), reset timer for onRegionEndChange. 
     if ((!isTouched && !getMapCenter().equals(previousMapCenter)) || (previousZoomLevel != getZoomLevel())) { 

      // If the region has just begun changing, fire off onRegionBeginChange event. 
      if (!regionChanging) { 
       regionChanging = true; 
       if (onRegionChangedListener != null) { 
        onRegionChangedListener.onRegionBeginChange(this, previousMapCenter, previousZoomLevel); 
       } 
      } 

      // Reset timer for onRegionEndChange. 
      removeCallbacks(onRegionEndChangeTask); 
      postDelayed(onRegionEndChangeTask, changeDuration); 
     } 
    } 

    private void init() { 
     changeDuration = DURATION_DEFAULT; 
     previousMapCenter = getMapCenter(); 
     previousZoomLevel = getZoomLevel(); 
    } 

    public void setOnRegionChangedListener(OnRegionChangedListener listener) { 
     onRegionChangedListener = listener; 
    } 

    public void setChangeDuration(int duration) { 
     changeDuration = duration; 
    } 

    public interface OnRegionChangedListener { 
     public abstract void onRegionBeginChange(ExMapView exMapView, GeoPoint geoPoint, int zoomLevel); 
     public abstract void onRegionEndChange(ExMapView exMapView, GeoPoint geoPoint, int zoomLevel); 
    } 
}