在android中自定义，禁用和空白地图

问题描述

我只想在地图上显示标记的半径部分，地图的其余部分必须是空白的。
就像标记半径是5公里一样，我希望只有地图的半径部分必须对用户可见，而地图的其余部分必须是空白的。

我已经阅读了Google Map Overlays，并且还搜索了像MapBox和Skobbler等各种SDK，但它们都没有提供我想要的功能。

在图片中，您可以看到只有标记周围的某些部分可见并且休息是空白。我想在android地图中实现此功能。

如果有人有任何解决方案或想法，请告诉我。

谢谢。 隐藏它并在其上绘制一个圆圈以仅显示所需位置的地图。

我已根据我的答案

• 
  $ b

  限制：

  
  
  
  
  
  • 此解决方案仅更新 onCameraChange 上的 HideOverlayView ，因此当用户缩放或平铺地图，地图上的其他位置可以显示
  
  
  • 计算半径的计算不考虑地图的旋转和倾斜度。 $ b
  
  

  I want to display only the radius part of marker on map and rest of the map must be blank.Like if Marker radius is 5 KM and i want that only that radius part of the map must be visible to user and rest of the map must be blank.

  I have read about Google Map Overlays and also search about various SDK Like MapBox and Skobbler but none of them provide the functionality that i want.

  In the image you can see that only some part around the marker is visible and rest is blank. I want to achieve this functionality in android Maps.

  If anyone has any solution or idea, please let me know.

  Thanks.

  解决方案

  You can add a View over the map that hides it and draw a circle on it to show only the desired locations.

  I have based my answers on

  • Draw transparent circle filled outside

  • Android - Google Maps inside CircleView

  • How can I draw a static target circle on Google Maps?

  MapsActivity:

  public class MapsActivity extends FragmentActivity implements GoogleMap.OnCameraChangeListener {
      private GoogleMap mMap;
      private HideOverlayView hideView;
      private List<Marker> visibleMarkers = new ArrayList<>();
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_maps);
  
          hideView = (HideOverlayView) findViewById(R.id.hideview);
  
          setUpMapIfNeeded();
      }
  
      @Override
      protected void onResume() {
          super.onResume();
          setUpMapIfNeeded();
      }
  
      @SuppressLint("NewApi")
      private void setUpMapIfNeeded() {
          if (mMap == null) {
              final SupportMapFragment f = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
              mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                      .getMap();
              if (mMap != null) {
                  setUpMap();
              }
          }
      }
  
      private void setUpMap() {
          mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
          mMap.getUiSettings().setAllGesturesEnabled(true);
          mMap.getUiSettings().setZoomControlsEnabled(true);
          mMap.getUiSettings().setMyLocationButtonEnabled(true);
          mMap.setMyLocationEnabled(true);
          mMap.setOnCameraChangeListener(this);
  
          mMap.moveCamera(CameraUpdateFactory.newCameraPosition(
                  CameraPosition.fromLatLngZoom(new LatLng(40.22861, -3.95567), 15)));
  
          visibleMarkers.add(mMap.addMarker(new MarkerOptions().position(
                  new LatLng(40.22861, -3.95567))));
          visibleMarkers.add(mMap.addMarker(new MarkerOptions().position(
                  new LatLng(40.22977, -3.95338))));
      }
  
      @Override
      public void onCameraChange(final CameraPosition cameraPosition) {
          List<Point> visiblePoints = new ArrayList<>();
          Projection projection = mMap.getProjection();
  
          for (Marker visibleMarker : visibleMarkers) {
              visiblePoints.add(projection.toScreenLocation(visibleMarker.getPosition()));
          }
  
          float radius = 150f; // meters
          Point centerPoint = projection.toScreenLocation(cameraPosition.target);
          Point radiusPoint = projection.toScreenLocation(
                  SphericalUtil.computeOffset(cameraPosition.target, radius, 90));
  
          float radiusPx = (float) Math.sqrt(Math.pow(centerPoint.x - radiusPoint.x, 2));
  
          hideView.reDraw(visiblePoints, radiusPx);
      }
  }
  

  HideOverlayView:

  public class HideOverlayView extends LinearLayout {
      private Bitmap windowFrame;
      private float radius = 0f;
      private List<Point> points;
  
      public HideOverlayView(Context context) {
          super(context);
      }
  
      public HideOverlayView(Context context, AttributeSet attrs) {
          super(context, attrs);
      }
  
      @Override
      protected void dispatchDraw(Canvas canvas) {
          super.dispatchDraw(canvas);
  
          createWindowFrame();
          canvas.drawBitmap(windowFrame, 0, 0, null);
      }
  
      @Override
      public boolean isEnabled() {
          return false;
      }
  
      @Override
      public boolean isClickable() {
          return false;
      }
  
      public void reDraw(List<Point> points, float radius) {
          this.points = points;
          this.radius = radius;
  
          invalidate();
      }
  
      protected void createWindowFrame() {
          windowFrame = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
          Canvas osCanvas = new Canvas(windowFrame);
  
          RectF outerRectangle = new RectF(0, 0, getWidth(), getHeight());
          Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
          paint.setColor(Color.BLACK);
          osCanvas.drawRect(outerRectangle, paint);
  
          if (radius > 0 && points != null) {
              for (Point point : points) {
                  paint.setColor(Color.TRANSPARENT);
                  paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
                  paint.setStyle(Paint.Style.FILL);
                  osCanvas.drawCircle(point.x, point.y, radius, paint);
              }
          }
      }
  
      @Override
      public boolean isInEditMode() {
          return true;
      }
  
      @Override
      protected void onLayout(boolean changed, int l, int t, int r, int b) {
          super.onLayout(changed, l, t, r, b);
          windowFrame = null;
      }
  }
  

  activity_maps.xml:

  <?xml version="1.0" encoding="utf-8"?>
  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                  xmlns:app="http://schemas.android.com/apk/res-auto"
                  xmlns:tools="http://schemas.android.com/tools"
                  android:layout_width="match_parent"
                  android:layout_height="match_parent"
                  android:orientation="vertical">
      <fragment
          android:id="@+id/map"
          android:name="mypackage.MySupportMapFragment"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          tools:context=".MapsActivity"/>
      <mypackage.HideOverlayView
          android:id="@+id/hideview"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_centerInParent="true"
          app:radius="150dp"/>
  </RelativeLayout>
  

  Result:

  Limitations:

  • This solution only updates the HideOverlayView on onCameraChange, so when the user zooms or pans the map, other locations on the map can be shown
  • The calculations made to compute the radius don't take into account rotations and tilts of the map

  这篇关于在android中自定义，禁用和空白地图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！