android中的自定义，禁用和空白地图 _android

【android中的自定义，禁用和空白地图】幼敏悟过人，读书辄成诵。这篇文章主要讲述android中的自定义，禁用和空白地图相关的知识，希望能为你提供帮助。
我想在地图上只显示标记的半径部分，而地图的其余部分必须为空白。就像标记半径是5公里并且我希望只有地图的半径部分必须对用户可见，并且地图的其余部分必须为空白。
我已经阅读了有关Google Map Overlays的信息，还搜索了各种类似MapBox和Skobbler的SDK，但它们都没有提供我想要的功能。

文章图片

在图像中，您可以看到标记周围只有部分可见，其余部分为空白。我想在android Maps中实现这个功能。
如果有人有任何解决方案或想法，请告诉我。
谢谢。
答案您可以在隐藏它的地图上添加View，并在其上绘制一个圆圈以仅显示所需的位置。
我的答案基于

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>

结果：