通过活动访问应用程序上下文数据

Question

这个问题可能有点复杂，但我会尽力解释。

基本上我试图通过我的应用程序获取最后一个位置（纬度、经度），所以我做了这样的事情：

public class GoogleLocation extends Activity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {

GoogleApiClient mGoogleApiClient = null;
Location mLastLocation = null;
LocationManager lm;
Double latitude;
Double longitude;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    connectLocation();
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    lm = (LocationManager) getSystemService(LOCATION_SERVICE);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},
                    30);
        }
    }
        Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if(location != null){
            longitude = location.getLongitude();
            latitude = location.getLatitude();
        }
        Log.d("IMHERE","IMHERE");
        Log.d("latitude",String.valueOf(latitude));

        final LocationListener locationListener = new LocationListener() {
            public void onLocationChanged(Location location) {
                longitude = location.getLongitude();
                latitude = location.getLatitude();
                //Log.d("latitudee",String.valueOf(latitude));
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        };

        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 10, locationListener);


    }


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

protected void onStop() {
    mGoogleApiClient.disconnect();
    super.onStop();
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}

public void connectLocation(){
    if (mGoogleApiClient == null) {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).build();
        mGoogleApiClient.connect();

        LocationRequest locationRequest = LocationRequest.create();
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        locationRequest.setInterval(30 * 1000);
        locationRequest.setFastestInterval(5 * 1000);
        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(locationRequest);

        //**************************
        builder.setAlwaysShow(true); //this is the key ingredient
        //**************************

        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());
        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                final LocationSettingsStates state = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the user
                        // a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    GoogleLocation.this, 1000);
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way to fix the
                        // settings so we won't show the dialog.
                        break;
                }
            }
        });
    }
}

@Override
public void onLocationChanged(Location location) {
    mLastLocation = location;
    Log.d("mLastLocation",String.valueOf(location.getLatitude()));
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
}

如果它通过 onLocationChanged 就可以正常工作，所以它第一次进入时需要几秒钟才能获得位置，第二次尝试时，我的应用程序已经获得了最后一个位置并且需要 10 秒以上到达新位置。

此时一切正常。

现在我想做的是运行在后台执行此操作，这就是为什么我将扩展更改为 activity，并尝试在后台使用 onLocationChanged 来更新我的位置。

类似于 this example.

每次我的应用程序检测到新位置时，我都想更新（在我的 class 中执行 setLocation 或其他操作）。

就像我说的，我想在每次启动我的应用程序时都这样做，这应该运行在后台，每次我访问这个 class 它应该检索我的最后一个位置，并且我想从不同的位置访问此 class。

我的完整代码：

public class GoogleLocation extends Activity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {

GoogleApiClient mGoogleApiClient = null;
Location mLastLocation = null;
LocationManager lm;
Double latitude;
Double longitude;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    connectLocation();
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    lm = (LocationManager) getSystemService(LOCATION_SERVICE);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},
                    30);
        }
    }
        Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if(location != null){
            longitude = location.getLongitude();
            latitude = location.getLatitude();
        }
        Log.d("IMHERE","IMHERE");
        Log.d("latitude",String.valueOf(latitude));

        final LocationListener locationListener = new LocationListener() {
            public void onLocationChanged(Location location) {
                longitude = location.getLongitude();
                latitude = location.getLatitude();
                //Log.d("latitudee",String.valueOf(latitude));
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        };

        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 10, locationListener);


    }


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

protected void onStop() {
    mGoogleApiClient.disconnect();
    super.onStop();
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}

public void connectLocation(){
    if (mGoogleApiClient == null) {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).build();
        mGoogleApiClient.connect();

        LocationRequest locationRequest = LocationRequest.create();
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        locationRequest.setInterval(30 * 1000);
        locationRequest.setFastestInterval(5 * 1000);
        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(locationRequest);

        //**************************
        builder.setAlwaysShow(true); //this is the key ingredient
        //**************************

        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());
        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                final LocationSettingsStates state = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the user
                        // a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    GoogleLocation.this, 1000);
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way to fix the
                        // settings so we won't show the dialog.
                        break;
                }
            }
        });
    }
}

@Override
public void onLocationChanged(Location location) {
    mLastLocation = location;
    Log.d("mLastLocation",String.valueOf(location.getLatitude()));
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
}

我该怎么做？

Answer 1

完整代码:

import android.Manifest;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.location.Criteria;
import android.location.Location;

import com.google.android.gms.location.LocationListener;

import android.location.LocationManager;
import android.media.Image;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
import android.support.v7.widget.SearchView;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
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.common.api.PendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationSettingsRequest;
import com.google.android.gms.location.LocationSettingsResult;
import com.google.android.gms.location.LocationSettingsStates;
import com.google.android.gms.location.LocationSettingsStatusCodes;

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

import static android.location.Criteria.POWER_HIGH;

public class MainActivity extends Activity implements  GoogleApiClient.OnConnectionFailedListener,
        GoogleApiClient.ConnectionCallbacks, ResultCallback<LocationSettingsResult> ,LocationListener {


    Double lat, lng;
    GoogleApiClient mGoogleApiClient;
    LocationRequest mLocationRequest;

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

        if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API)
                    .build();
        } else {
            mGoogleApiClient.connect();
        }

    }




    protected LocationRequest createLocationRequest() {
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(10000);
        mLocationRequest.setFastestInterval(5000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        return mLocationRequest;
    }

    @Override
    public void onConnected(Bundle bundle) {
        Log.e("Connection", "GOOGLE API Connected");


        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(createLocationRequest());
        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient,
                        builder.build());
        result.setResultCallback(this);

    }

    protected void getPhoneLocation() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(
                mGoogleApiClient, mLocationRequest, this);

    }

    @Override
    public void onConnectionSuspended(int i) {

        Log.e("Connection","GOOGLE API Suspended");
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

        Log.e("Connection","GOOGLE API Failed : " + connectionResult.toString() );
    }

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


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

    @Override
    public void onResult(LocationSettingsResult locationSettingsResult) {

        final Status status = locationSettingsResult.getStatus();

        switch (status.getStatusCode()) {
            case LocationSettingsStatusCodes.SUCCESS:
                if (!(ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) ==
                        PackageManager.PERMISSION_GRANTED &&
                        ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) ==
                                PackageManager.PERMISSION_GRANTED)) {

                    ActivityCompat.requestPermissions(this,
                            new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},
                            222);
                }
                else
                {
                    getPhoneLocation();
                }
                // All location settings are satisfied. The client can
                // initialize location requests here.
                break;
            case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                // Location settings are not satisfied, but this can be fixed
                // by showing the user a dialog.
                try {
                    // Show the dialog by calling startResolutionForResult(),
                    // and check the result in onActivityResult().
                    status.startResolutionForResult(
                            MainActivity.this,
                            111);
                } catch (IntentSender.SendIntentException e) {
                    // Ignore the error.
                }
                break;
            case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                // Location settings are not satisfied. However, we have no way
                // to fix the settings so we won't show the dialog.
                break;
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.e("Activity","Result");
        if(requestCode != 333) {
            if (!(ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) ==
                    PackageManager.PERMISSION_GRANTED &&
                    ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) ==
                            PackageManager.PERMISSION_GRANTED)) {

                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},
                        222);
            } else {
                getPhoneLocation();
            }
        }
        else
        {
            if(resultCode == RESULT_OK) {
                finish();
            }
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        if(requestCode == 222) {
            if (grantResults.length != 0) {
                getPhoneLocation();
            }
        }
    }

    @Override
    public void onLocationChanged(Location location) {
        lat = location.getLatitude();
        lng = location.getLongitude();
        }
    } `

此代码让您在 10 到 5 秒的时间间隔内获得位置，并且它们通过 onLocationChanged ... GetLastKnowLocation 为您提供设备的最后已知位置...所以有时它可能 return null.. .

代码说明
OnCreate 中的此代码块连接到 Google API 客户端，回调指向 activity.

if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API)
                    .build();
        } else {
            mGoogleApiClient.connect();
        }

这很重要

public class MainActivity extends Activity implements  GoogleApiClient.OnConnectionFailedListener,
        GoogleApiClient.ConnectionCallbacks, ResultCallback<LocationSettingsResult> ,LocationListener {

创建一个像你这样的位置请求，间隔

protected LocationRequest createLocationRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(10000);
    mLocationRequest.setFastestInterval(5000);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    return mLocationRequest;
}

当 GOOGLE API 连接时检查设置和权限

 @Override
    public void onConnected(Bundle bundle) {
    Log.e("Connection", "GOOGLE API Connected");


    LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
            .addLocationRequest(createLocationRequest());
    PendingResult<LocationSettingsResult> result =
            LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient,
                    builder.build());
    result.setResultCallback(this);

}

设置回调RETURNS到ACTIVITY这里 在此块中，我们检查设置的状态并查看它们是否 return 成功我们检查权限...如果我们有权访问该位置...然后我们 getPhoneLocation() OPTION A ...如果我们没有权限，我们会请求权限，然后回调转到 选项 B

`@Override`
    public void onResult(LocationSettingsResult locationSettingsResult) {

    final Status status = locationSettingsResult.getStatus();

    switch (status.getStatusCode()) {
        case LocationSettingsStatusCodes.SUCCESS:
            if (!(ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) ==
                    PackageManager.PERMISSION_GRANTED &&
                    ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) ==
                            PackageManager.PERMISSION_GRANTED)) {

                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},
                        222);
            }
            else
            {
                getPhoneLocation();
            }
            // All location settings are satisfied. The client can
            // initialize location requests here.
            break;
        case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
            // Location settings are not satisfied, but this can be fixed
            // by showing the user a dialog.
            try {
                // Show the dialog by calling startResolutionForResult(),
                // and check the result in onActivityResult().
                status.startResolutionForResult(
                        MainActivity.this,
                        111);
            } catch (IntentSender.SendIntentException e) {
                // Ignore the error.
            }
            break;
        case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
            // Location settings are not satisfied. However, we have no way
            // to fix the settings so we won't show the dialog.
            break;
    }
}

选项 B 在此块中，我们通过检查用户权限获得 Return ...如果他接受了位置请求，我们继续获取 PhoneLocation ...如果否，我们关闭 activity.

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.e("Activity","Result");
        if(requestCode != 333) {
            if (!(ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) ==
                    PackageManager.PERMISSION_GRANTED &&
                    ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) ==
                            PackageManager.PERMISSION_GRANTED)) {

                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},
                        222);
            } else {
                getPhoneLocation();
            }
        }
        else
        {
            if(resultCode == RESULT_OK) {
                finish();
            }
        }
    }

添加位置请求（选项 A）

protected void getPhoneLocation() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(
                mGoogleApiClient, mLocationRequest, this);

    }

现在你有位置 现在，只要 Activity 打开，您就可以在给定的时间间隔内找到位置。

 @Override
    public void onLocationChanged(Location location) {
        lat = location.getLatitude();
        lng = location.getLongitude();
        }

通过活动访问应用程序上下文数据

Access Application context data through activities

java

android

geolocation

android-location