我厌倦了在Android中使用新的权限系统，因此开始寻找其他选项。 permissionsDispatch库看起来很神奇，但我无法让它工作。我一直在尝试过去两个小时让代码无效。这是一个相当小而简单的例子：
@RuntimePermissions
public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
private static final int MY_REQUEST_PERMISSION_COARSE_LOCATION = 45;
public static final String TAG = "MAINACTIVITYITS";
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GoogleApiBuilder();
}
public void GoogleApiBuilder() {
// Create an instance of GoogleAPIClient.
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
}
@Override
protected void onStart() {
mGoogleApiClient.connect();
super.onStart();
}
@Override
protected void onStop() {
mGoogleApiClient.disconnect();
super.onStop();
}
@SuppressWarnings("MissingPermission")
@NeedsPermission(Manifest.permission.ACCESS_FINE_LOCATION)
public void mLocationSetter(){
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
}
@Override
public void onConnected(@Nullable Bundle bundle) {
mLocationSetter();
Log.i(TAG, mLastLocation.getLatitude() + "");
Toast.makeText(this, mLastLocation.getLatitude() + "" , Toast.LENGTH_LONG).show();
}
@OnShowRationale(Manifest.permission.ACCESS_COARSE_LOCATION)
public void locationRationale(PermissionRequest request){
showRationaleDialog(R.string.permission_coarse_rationale, request);
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
// NOTE: delegate the permission handling to generated method
MainActivityPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults);
}
private void showRationaleDialog(@StringRes int messageResId, final PermissionRequest request){
new AlertDialog.Builder(this)
.setPositiveButton(R.string.button_allow, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
request.proceed();
}
})
.setNegativeButton(R.string.button_deny, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
request.cancel();
}
})
.setCancelable(false)
.setMessage(messageResId)
.show();
}
}
我的问题来自于mLastLocation实例变量，即使在使用@NeedsPermission标记进行注释后也会返回null，并且根本没有显示基本原理。基本上，我要做的是使用相同的教程来获取Google https://developer.android.com/training/location/retrieve-current.html中的最后一个已知位置，但使用此库而不必编写所有权限代码。我错过了什么吗？我想要的只是最后一个已知位置。