固定Android Google地图上的标记大小

Question

有没有可能使标记静态不动呢？ 当缩放改变时，我不需要增加/减小标记大小。 我知道有'groundoverlay'这个选项，但在这里不适用。 结果应该像这样：

- inaps

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为什么？如果您再缩小一次，标记将消失。 - user6490462

没问题。但是目前我必须设置标记的比例，就像图片上展示的那样。它不能是动态的，必须作为地面叠加层。 - inaps

@inaps：你能解决这个问题吗？我也遇到了同样的问题。 - user2234

官方文档中指出：“标记不会根据缩放级别改变大小。如果需要此效果，请使用地面叠加层”。为什么地面叠加层不可接受？ - Ben P.

为什么 GroundOverlay "这里不是一个选项"？ - serg3z

Answer 1

Ben P 在他的评论中是正确的："标记不会根据缩放级别改变大小"。但是通过在每个缩放级别的 onCameraIdle() 中删除并重新创建具有自定义图标大小的标记，可以实现此标记行为。使用：

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {

    private static final String TAG = MainActivity.class.getSimpleName();
    private static final int DIAMETER_IN_METERS = 300;

    private final LatLng MARKER_LOCATION = new LatLng(37.762555, -122.244221);

    private GoogleMap mGoogleMap;
    private MapFragment mMapFragment;

    private Marker mMarker = null;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mMapFragment = (MapFragment) getFragmentManager()
                .findFragmentById(R.id.map_fragment);
        mMapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;

        mGoogleMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
            @Override
            public void onCameraIdle() {

                if (mMarker != null) {
                    mMarker.remove();
                }
                mMarker = createResizedMarker(MARKER_LOCATION);
            }
        });
        mGoogleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(MARKER_LOCATION, 16));
    }

    private Marker createResizedMarker(LatLng marker_location) {
        // get vector drawable
        final Drawable iconDrawable = getResources().getDrawable(R.drawable.ic_letter_m);
        // calc map resolution (meters per pixel) for current zoom level for details see e.g. https://msdn.microsoft.com/en-us/library/aa940990.aspx
        final double meters_per_pixel = (Math.cos(mGoogleMap.getCameraPosition().target.latitude * Math.PI / 180) * 2 * Math.PI * 6378137) / (256 * Math.pow(2, mGoogleMap.getCameraPosition().zoom));
        // calc marker icon diameter in pixels
        final int diameter = (int)(DIAMETER_IN_METERS / meters_per_pixel);
        // create marker icon bitmap for current scale
        final Bitmap bitmap = Bitmap.createBitmap(diameter, diameter, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        iconDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        iconDrawable.draw(canvas);

        Marker marker = mGoogleMap.addMarker(new MarkerOptions()
                .position(MARKER_LOCATION)
                .anchor(0.5f, 0.5f)
                .icon(BitmapDescriptorFactory.fromBitmap(bitmap)));

        return marker;
    }
}

并且使用R.drawable.ic_letter_m - xml矢量可缩放图片（以达到完美的缩放效果），例如：

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="512dp"
        android:height="512dp"
        android:viewportWidth="512"
        android:viewportHeight="512">

    <path
        android:name="canvas_background"
        android:pathData="M -1 -1 H 581 V 401 H -1 V -1 Z" />
    <path
        android:name="SVGCleanerId_0"
        android:fillColor="#54BBFF"
        android:pathData="M256,0l-61.811005,256l61.811005,256c141.384979,0 256,-114.61499
256,-256s-114.61499,-256 -256,-256z" />
    <path
        android:name="SVGCleanerId_1"
        android:fillColor="#8DD2FF"
        android:pathData="M0,256c0,141.384979 114.614998,256 256,256l0,-512c-141.385002,0 -256,114.614998
-256,256z" />
    <path
        android:name="svg_1"
        android:fillColor="#C6E8FF"
        android:pathData="M256,30.905001l0,450.188993c124.31601,0 225.095001,-100.777985
225.095001,-225.095001s-100.778992,-225.093992 -225.095001,-225.093992z" />
    <path
        android:name="svg_2"
        android:fillColor="#FFFFFF"
        android:pathData="M450.188995,256c0,-124.315994 -86.94101,-225.094999
-194.188995,-225.094999c-124.315994,0 -225.094999,100.779005
-225.094999,225.094999s100.779005,225.095001 225.094999,225.095001c107.247986,0
194.188995,-100.778992 194.188995,-225.095001z" />
    <path
        android:name="svg_3"
        android:fillColor="#54BBFF"
        android:pathData="M306.993988,395.589996c-11.378998,0 -20.604004,-9.223999
-20.604004,-20.604004l0,-137.592987l-11.453003,26.722992c-3.246002,7.576019
-10.694977,12.488007 -18.937988,12.488007c-8.240997,0 -15.69101,-4.912018
-18.938004,-12.488007l-11.453003,-26.722992l0,137.593018c0,11.378998
-9.223999,20.603973 -20.604004,20.603973c-11.378998,0 -20.603989,-9.223999
-20.603989,-20.603973l0,-237.972015c0,-9.782997 6.878998,-18.215996
16.460999,-20.182999c9.584,-1.968002 19.227005,3.075005
23.080002,12.065994l32.059006,74.798004l32.056,-74.796997c3.852997,-8.990997
13.502014,-14.032997 23.079987,-12.066002c9.583008,1.968002 16.460999,10.401001
16.460999,20.183006l0,237.971985c0.001007,11.377991 -9.223999,20.602997
-20.602997,20.602997z" />
    <path
        android:name="SVGCleanerId_0_1_"
        android:fillColor="#F655A0"
        android:pathData="M256,0l-61.811005,256l61.811005,256c141.384979,0 256,-114.61499
256,-256s-114.61499,-256 -256,-256z" />
    <path
        android:name="SVGCleanerId_1_1_"
        android:fillColor="#F655A0"
        android:pathData="M0,256c0,141.384979 114.614998,256 256,256l0,-512c-141.385002,0 -256,114.614998
-256,256z" />
    <path
        android:name="svg_8"
        android:fillColor="#FFFFFF"
        android:pathData="M335.771271,393.589996c-17.577087,0 -31.826935,-9.223999
-31.826935,-20.604004l0,-137.592987l-17.691406,26.722992c-5.014069,7.576019
-16.520477,12.488007 -29.253418,12.488007c-12.729828,0 -24.237839,-4.912018
-29.253448,-12.488007l-17.691406,-26.722992l0,137.593018c0,11.378998
-14.248276,20.603973 -31.82692,20.603973c-17.577087,0 -31.826889,-9.223999
-31.826889,-20.603973l0,-237.972015c0,-9.782997 10.625946,-18.215996
25.427231,-20.182999c14.804367,-1.968002 29.699875,3.075005
35.651581,12.065994l49.521408,74.798004l49.516754,-74.796997c5.951721,-8.990997
20.856506,-14.032997 35.651581,-12.066002c14.802826,1.968002 25.427216,10.401001
25.427216,20.183006l0,237.971985c0.001556,11.377991 -14.24826,20.602997
-31.825348,20.602997z" />
</vector>

你有一个类似如下的东西:

但事实上，Ground Overlay 可以从容应对所有这些任务。使用 Ground Overlays 更好 (至少可以获得更好的性能和平滑的缩放)。如果需要，在任何时间你都可以重新创建 Ground Overlays(使用不同的位图或标记大小)，例如绘制汽车运动等。你还可以像标记一样旋转 Ground Overlays,使用.setBearing()方法。

- Andrii Omelchenko

Answer 2

我曾经遇到过同样的问题，使用以下代码解决了这个问题。你可以使用以下代码来创建一个固定大小的标记。在我的研究中，我们只有位图选项。

int height = 100;
int width = 100;
BitmapDrawable bitmapdraw=(BitmapDrawable)getResources().getDrawable(R.mipmap.marker);
Bitmap b=bitmapdraw.getBitmap();
Bitmap smallMarker = Bitmap.createScaledBitmap(b, width, height, false);

要添加市场，请使用以下代码：

gMap.addMarker(new MarkerOptions()
                        .position(POSITION)
                        .title("Title")
                        .icon(BitmapDescriptorFactory.fromBitmap(smallMarker))
                );

- aanshu

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如果您发现以上任何解决方案有帮助，请接受最相关的答案，以便其他开发人员也能受益。 - aanshu