我已经在Android Studio中集成了Google Maps API，它还可以找到当前位置，但我想提高缩放级别，以便我可以更清晰地查看当前位置并进行精确定位。如何提高缩放级别？
你可以在下面找到我的代码：
package com.example.umar.testgoogle;
import android.location.Location;
import android.content.IntentSender;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
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.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener {
public static final String TAG = MapsActivity.class.getSimpleName();
/*
* Define a request code to send to Google Play services
* This code is returned in Activity.onActivityResult
*/
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
private GoogleMap mMap; // Might be null if Google Play services APK is
// not available.
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
setUpMapIfNeeded();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
// Create the LocationRequest object
mLocationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(10 * 1000) // 10 seconds, in milliseconds
.setFastestInterval(1 * 1000); // 1 second, in milliseconds
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
mGoogleApiClient.connect();
}
@Override
protected void onPause() {
super.onPause();
if (mGoogleApiClient.isConnected()) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
mGoogleApiClient.disconnect();
}
}
/**
* Sets up the map if it is possible to do so (i.e., the Google Play
* services APK is correctly installed) and the map has not already
* been instantiated.. This will ensure that we only ever call
* {@link #setUpMap()} once when {@link #mMap} is not null.
* <p/>
* If it isn't installed {@link SupportMapFragment} (and
* {@link com.google.android.gms.maps.MapView MapView}) will show a
* prompt for the user to install/update the Google Play services
* APK on their device.
* <p/>
* A user can return to this FragmentActivity after following the
* prompt and correctly installing/updating/enabling the Google
* Play services. Since the FragmentActivity may not have been
* completely destroyed during this process (it is likely that it
* would only be stopped or paused), {@link #onCreate(Bundle)} may
* not be called again so we should call this method in
* {@link #onResume()} to guarantee that it will be called.
*/
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
setUpMap();
}
}
}
/**
* This is where we can add markers or lines, add listeners or move
* the camera. In this case, we just add a marker near Africa.
* <p/>
* This should only be called once and when we are sure
* that {@link #mMap} is not null.
*/
private void setUpMap() {
mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
}
private void handleNewLocation(Location location) {
Log.d(TAG, location.toString());
double currentLatitude = location.getLatitude();
double currentLongitude = location.getLongitude();
LatLng latLng = new LatLng(currentLatitude, currentLongitude);
//mMap.addMarker(new MarkerOptions().position(new LatLng(currentLatitude, currentLongitude)).title("Current Location"));
MarkerOptions options = new MarkerOptions()
.position(latLng)
.title("I am here!");
mMap.addMarker(options);
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
}
@Override
public void onConnected(Bundle bundle) {
Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (location == null) {
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
else {
handleNewLocation(location);
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
/*
* Google Play services can resolve some errors it detects.
* If the error has a resolution, try sending an Intent to
* start a Google Play services activity that can resolve
* error.
*/
if (connectionResult.hasResolution()) {
try {
// Start an Activity that tries to resolve the error
connectionResult.startResolutionForResult(
this, CONNECTION_FAILURE_RESOLUTION_REQUEST);
/*
* Thrown if Google Play services canceled the original
* PendingIntent
*/
}
catch (IntentSender.SendIntentException e) {
// Log the error
e.printStackTrace();
}
}
else {
/*
* If no resolution is available, display a dialog to the
* user with the error.
*/
Log.i(TAG, "Location services connection failed with code " +
connectionResult.getErrorCode());
}
}
@Override
public void onLocationChanged(Location location) {
handleNewLocation(location);
}
}
改变自：
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
至：
float zoomLevel = 16.0f; //This goes up to 21
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, zoomLevel));
public static CameraUpdate newLatLngZoom（LatLng latLng，float zoom）
返回一个CameraUpdate，它将屏幕中心移动到LatLng对象指定的纬度和经度，并移动到给定的缩放级别。
参数latLng包含所需纬度和经度的LatLng对象。缩放所需的缩放级别，范围为2.0到21.0。低于此范围的值设置为2.0，高于此值的值设置为21.0。增加值以放大。并非所有区域都具有最大缩放级别的图块。返回包含转换的CameraUpdate。
或者您也可以使用animateCamerma方法获得动画缩放效果。
// This is method returns the lastKnownlocation and store it in location object from where then you can retrive latitute and longitude.
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 20.0f));