android - 如何使用谷歌 API 客户端在谷歌地图 Android 中显示我的当前位置

Question

我想在 map 上显示我的位置并放大它。我想使用 GoolgeAPIClient。 map 渲染并创建了指针，但位置错误。我觉得甚至在调用 GoogleAPIClient 的 onConnected 方法之前就先执行了 onMapReady。请帮助这是我的代码。

import android.location.Location;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;
import com.google.android.gms.maps.model.MarkerOptions;


public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
    protected static final String TAG = "MainActivity";

    /**
     * Provides the entry point to Google Play services.
     */
    protected GoogleApiClient mGoogleApiClient;

    /**
     * Represents a geographical location.
     */
    protected Location mLastLocation;

    protected String mLatitudeLabel;
    protected String mLongitudeLabel;
    protected TextView mLatitudeText;
    protected TextView mLongitudeText;
    protected double dLat;
    protected double dLong;



    private GoogleMap mMap;

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

        buildGoogleApiClient();
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        LatLng myLocation = new LatLng(dLat, dLong);
        mMap.addMarker(new MarkerOptions().position(myLocation).title("You are here"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(myLocation));
    }

    /**
     * BEGIN
     */
    /**
     * Builds a GoogleApiClient. Uses the addApi() method to request the LocationServices API.
     */
    protected synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }

    /**
     * Runs when a GoogleApiClient object successfully connects.
     */
    @Override
    public void onConnected(Bundle connectionHint) {
        // Provides a simple way of getting a device's location and is well suited for
        // applications that do not require a fine-grained location and that do not need location
        // updates. Gets the best and most recent location currently available, which may be null
        // in rare cases when a location is not available.
        mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if (mLastLocation != null) {

            dLat = mLastLocation.getLatitude();


            dLong = mLastLocation.getLongitude();
        } else {
            Toast.makeText(this, R.string.no_location_detected, Toast.LENGTH_LONG).show();
        }
    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {
        // Refer to the javadoc for ConnectionResult to see what error codes might be returned in
        // onConnectionFailed.
        Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + result.getErrorCode());
    }


    @Override
    public void onConnectionSuspended(int cause) {
        // The connection to Google Play services was lost for some reason. We call connect() to
        // attempt to re-establish the connection.
        Log.i(TAG, "Connection suspended");
        mGoogleApiClient.connect();
    }
}



11-17 01:30:39.482 30546-30546/com.gioinout.giohanda E/dalvikvm: Could not find class 'android.app.AppOpsManager', referenced from method com.google.android.gms.common.GooglePlayServicesUtil.zzb
11-17 01:30:39.538 30546-30569/com.gioinout.giohanda E/GMPM: getGoogleAppId failed with status: 10
11-17 01:30:39.539 30546-30569/com.gioinout.giohanda E/GMPM: Uploading is not possible. App measurement disabled
11-17 01:30:39.579 30546-30546/com.gioinout.giohanda E/dalvikvm: Could not find class 'android.app.AppOpsManager', referenced from method com.google.android.gms.common.ma.a
11-17 01:30:39.684 30546-30546/com.gioinout.giohanda E/dalvikvm: Could not find class 'android.app.AppOpsManager', referenced from method com.google.android.gms.common.lt.a
11-17 01:30:40.226 30546-30577/com.gioinout.giohanda E/NativeCrypto: ssl=0x5d26beb8 cert_verify_callback x509_store_ctx=0x60700ab0 arg=0x0
11-17 01:30:40.227 30546-30577/com.gioinout.giohanda E/NativeCrypto: ssl=0x5d26beb8 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_ECDSA
11-17 01:30:42.982 30546-30579/com.gioinout.giohanda E/NativeCrypto: ssl=0x6151f770 cert_verify_callback x509_store_ctx=0x60910ab0 arg=0x0
11-17 01:30:42.983 30546-30579/com.gioinout.giohanda E/NativeCrypto: ssl=0x6151f770 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_ECDSA

Answer 1

针对 api-23 及更高版本:

查看答案here .

针对 api-22 及更低版本:

这是满足您需要的完整 Activity 代码，my other answer here 的修改版本.它在 Activity 加载时注册一个位置监听器，然后当每个位置更改事件发生时，它会添加一个 Marker 并动画 map 以当前位置为中心。

这里的关键是等到 onMapReady() 回调发生后再请求位置更新。

这是完整的 Activity 代码:

public class MainActivity extends AppCompatActivity implements
        OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {

    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;

    LatLng latLng;
    GoogleMap mGoogleMap;
    SupportMapFragment mFragment;
    Marker currLocationMarker;

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

        mFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap gMap) {
       mGoogleMap = gMap;
       mGoogleMap.setMyLocationEnabled(true);

       buildGoogleApiClient();

       mGoogleApiClient.connect();

    }

    protected synchronized void buildGoogleApiClient() {
        Toast.makeText(this,"buildGoogleApiClient",Toast.LENGTH_SHORT).show();
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    public void onConnected(Bundle bundle) {
        Toast.makeText(this,"onConnected",Toast.LENGTH_SHORT).show();
        Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                mGoogleApiClient);
        if (mLastLocation != null) {
            //place marker at current position
            //mGoogleMap.clear();
            latLng = new LatLng(mLastLocation.getLatitude(), mLastLocation.getLongitude());
            MarkerOptions markerOptions = new MarkerOptions();
            markerOptions.position(latLng);
            markerOptions.title("Current Position");
            markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
            currLocationMarker = mGoogleMap.addMarker(markerOptions);
        }

        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(5000); //5 seconds
        mLocationRequest.setFastestInterval(3000); //3 seconds
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
        //mLocationRequest.setSmallestDisplacement(0.1F); //1/10 meter

        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);



    }

    @Override
    public void onConnectionSuspended(int i) {
        Toast.makeText(this,"onConnectionSuspended",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Toast.makeText(this,"onConnectionFailed",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onLocationChanged(Location location) {

        //place marker at current position
        //mGoogleMap.clear();
        if (currLocationMarker != null) {
            currLocationMarker.remove();
        }
        latLng = new LatLng(location.getLatitude(), location.getLongitude());
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(latLng);
        markerOptions.title("Current Position");
        markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
        currLocationMarker = mGoogleMap.addMarker(markerOptions);

        Toast.makeText(this,"Location Changed",Toast.LENGTH_SHORT).show();

         //zoom to current position:
         mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11));

        //If you only need one location, unregister the listener
        //LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);

    }

}