如何从谷歌地图标记中获取视图？

Question

我想将showcaseview 添加到android 地图上的标记！？ 展示库以视图为论据。 如何从 Marker 获取视图？

我正在尝试这段代码

new GuideView.Builder(this)
    .setTitle("Guide Title Text")
    .setContentText("Guide Description Text\n .....Guide Description Text\n .....Guide Description Text .....")
    .setGravity(Gravity.auto) //optional
    .setDismissType(DismissType.anywhere) //optional - default DismissType.targetView
    .setTargetView(view)
    .setContentTextSize(12)//optional
    .setTitleTextSize(14)//optional
    .build()
    .show();

它在 setTargetView 中将视图作为参数，而不是标记对象

这是我想使用的库 https://github.com/mreram/ShowCaseView

Answer 1

Marker 不是视图，您无法从中获取View。但无论如何，您可以创建虚拟透明 View 并将其以编程方式放置在选定的标记上，然后通过 setTargetView 方法将其传递给 ShowCaseView 库。因此，您需要围绕 MapFragment 或 MapView 的根视图，例如 RelativeLayout (activity_main.xml)：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/mapview_root"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="<YOUR_PACKAGE_NAME>.MainActivity">

    <com.google.android.gms.maps.MapView android:id="@+id/mapview"
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        />

</RelativeLayout>

和虚拟透明视图布局 (transparent_layout.xml)：

<?xml version="1.0" encoding="utf-8"?>
<View
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="20dp"  <- adjust size programmatically or set to default size of Marker
    android:layout_height="30dp"
    android:layout_centerInParent="true"
    android:background="@android:color/transparent">
</View>

比，例如MainActivity，您需要获取根布局并膨胀虚拟透明视图，以及选择标记时（例如，单击）时，您应该获取所选Marker的当前屏幕坐标，并将虚拟透明视图放在完全覆盖。对于RelativeLayout，可以通过setLeft() 来完成x-coordinate 和setTop() 对于y-coordinate（当然你需要根据Marker 锚点调整偏移量）。类似的东西：

public class MainActivity extends AppCompatActivity {

    private static final String MAP_VIEW_BUNDLE_KEY = "MapViewBundleKey";
    static final LatLng KYIV = new LatLng(50.450311, 30.523730);

    private GoogleMap mGoogleMap;
    private RelativeLayout mMapViewRoot;
    private MapView mGoogleMapView;

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

        Bundle mapViewBundle = null;
        if (savedInstanceState != null) {
            mapViewBundle = savedInstanceState.getBundle(MAP_VIEW_BUNDLE_KEY);
        }

        mMapViewRoot = (RelativeLayout) findViewById(R.id.mapview_root);
        // dummy transparent view
        final View transparentView = View.inflate(getApplicationContext(), R.layout.transparent_view, mMapViewRoot);

        mGoogleMapView = (MapView) findViewById(R.id.mapview);
        mGoogleMapView.onCreate(mapViewBundle);
        mGoogleMapView.getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(GoogleMap googleMap) {
                mGoogleMap = googleMap;
                mGoogleMap.addMarker(new MarkerOptions().position(KYIV).title("Kyiv"));
                mGoogleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
                    @Override
                    public boolean onMarkerClick(Marker marker) {
                        // get screen coordinates of the marker
                        Projection projection = mGoogleMap.getProjection();
                        Point viewPosition = projection.toScreenLocation(marker.getPosition());

                        // place dummy transparent view over the marker
                        transparentView.setLeft(viewPosition.x);
                        transparentView.setTop(viewPosition.y);
                        return false;
                    }
                });

                mGoogleMap.animateCamera(CameraUpdateFactory.newLatLng(KYIV));

                ...

            }
        });

    }
...

当然这只是一个想法的例子，你应该改进标记大小、锚点等的代码。