忍受我，我是一名优秀的java开发人员，但我一直在学习android一个月。我目前正在创建一个应用，其中应用的一个关键元素是借助Google API位置服务分享您当前的位置。
我找到了this关于如何开始使用android中的位置概念的精彩指南。有些人可能认为它有点过时了，现在已经2岁了，但我想我还是可以尝试一下。
尽管我非常喜欢android studio，但我遇到了很多复杂的问题，我几乎觉得放弃了。例如，构建器抱怨我有超过64k的方法引用，我查找了问题，并在gradle文件中找到了一个带有一个衬垫的解决方法。后来我遇到了堆分配的问题，而且我不得不只是粘贴这个衬里，以便为我的应用分配更多的空间（没有解释这个功能的地方，你应该把它扔进去！）。
最后我的应用程序启动并在我的手机上运行，但是我没有看到一张带有我当前位置标记的漂亮地图，而是我看到的是一个白色屏幕，左下角有谷歌文字。我所能做的只是想知道，出了什么问题？
已完成的工作清单：
- 我有API密钥，并将其正确放入我的清单中 - 我紧跟着循序渐进的指南 - 我尝试使用Log并使用标记每个方法
来调试logcat我最后的希望是与你们分享这个，并希望一些更有经验的人会指出我的错误！
所以就这样了。
这是MapsActivity类：
Imports...
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener,
LocationListener
{
private GoogleMap mMap;
private GoogleApiClient mGoogleApiClient;
public static final String TAG = MapsActivity.class.getSimpleName();
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
private LocationRequest mLocationRequest;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// 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);
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();
mGoogleApiClient.connect();
}
@Override
protected void onPause()
{
super.onPause();
if (mGoogleApiClient.isConnected())
{
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
mGoogleApiClient.disconnect();
}
}
/**
* 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;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
@Override
public void onConnected(@Nullable Bundle bundle) {
Log.i(TAG, "Location services connected");
try
{
//if we get permissions from user to use this service, this will be executed
Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (location == null)
{
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
else
{
handleNewLocation(location);
};
}
catch(SecurityException e)
{
//here we did not get the permission
Log.i(TAG, "Did not get permissions");
}
}
@Override
public void onConnectionSuspended(int i) {
Log.i(TAG, "Location services suspended. Please reconnect");
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
if (connectionResult.hasResolution()) {
try
{
// Start an Activity that tries to resolve the error
connectionResult.startResolutionForResult(this, CONNECTION_FAILURE_RESOLUTION_REQUEST);
}
catch (IntentSender.SendIntentException e)
{
e.printStackTrace();
}
}
else
{
Log.i(TAG, "Location services connection failed with code " + connectionResult.getErrorCode());
}
}
private void handleNewLocation(Location location)
{
Log.d(TAG, "heresthelocation "+location.toString());
double currentLatitude = location.getLatitude();
double currentLongitude = location.getLongitude();
LatLng latLng = new LatLng(currentLatitude, currentLongitude);
MarkerOptions options = new MarkerOptions()
.position(latLng)
.title("I am here!");
mMap.addMarker(options);
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
}
@Override
public void onLocationChanged(Location location)
{
handleNewLocation(location);
}
}
如果需要，这是我的androidmanifest：
<?xml version="1.0" encoding="utf-8"?>
<!-- To auto-complete the email text field in the login form with the user's emails -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_PROFILE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar"></activity>
<activity
android:name=".MapsActivity"
android:label="@string/title_activity_login">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!--
The API key for Google Maps-based APIs is defined as a string resource.
(See the file "res/values/google_maps_api.xml").
Note that the API key is linked to the encryption key used to sign the APK.
You need a different API key for each encryption key, including the release key that is used to
sign the APK for publishing.
You can define the keys for the debug and release targets in src/debug/ and src/release/.
-->
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="@string/google_maps_key" />
</application>