Question

我在运行应用程序时没有收到任何错误，但我也没有看到任何日志消息。下面是我应该记录该位置的代码部分：

@Override
    public void onLocationChanged(Location location) {
        mCurrentLocation = location;
        mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
        Log.i("location", location.toString());
//        updateUI();
    }

继承我的完整课程代码：

package com.example.haotian.tutorial32;

import android.content.Intent;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

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.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

import java.text.DateFormat;
import java.util.Date;

public class MapsActivity extends FragmentActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
    protected GoogleApiClient mGoogleApiClient;
    protected LocationRequest mLocationRequest;
    protected Location mCurrentLocation;
    protected String mLastUpdateTime;
    protected TextView mLastUpdateTimeTextView;
    protected TextView mLatitudeTextView;
    protected TextView mLongitudeTextView;

    public static final String TAG = "MapsActivity";
    public static final int THUMBNAIL = 1;



    private GoogleMap mMap; // Might be null if Google Play services APK is not available.
    private Button picButton; //takes user to camera


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

        createLocationRequest();
        buildGoogleApiClient();

        picButton = (Button) findViewById(R.id.photobutton);

        picButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });
    }


    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    /**
     * 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(20, 20)).title("EECS397/600"));
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {


    }

    @Override
    public void onConnected(Bundle connectionHint) {
        startLocationUpdates();
    }

    @Override
    public void onConnectionSuspended(int cause) {

    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {

    }

    @Override
    public void onLocationChanged(Location location) {
        mCurrentLocation = location;
        mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
        Log.i("location", location.toString());
//        updateUI();
    }

//    private void updateUI() {
//        mLatitudeTextView.setText(String.valueOf(mCurrentLocation.getLatitude()));
//        mLongitudeTextView.setText(String.valueOf(mCurrentLocation.getLongitude()));
//        mLastUpdateTimeTextView.setText(mLastUpdateTime);
//    }

    protected void startLocationUpdates() {
        LocationServices.FusedLocationApi.requestLocationUpdates(
                mGoogleApiClient, mLocationRequest, this);
    }

    protected synchronized void buildGoogleApiClient() {
        Log.i(TAG, "Building GoogleApiClient");
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener((GoogleApiClient.OnConnectionFailedListener) this)
                .addApi(LocationServices.API)
                .build();

        createLocationRequest();

    }

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

}

Answer 1

您需要调用connect()方法才能调用onConnected()，这是您正确开始位置更新的地方。

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

    createLocationRequest();
    buildGoogleApiClient();
    mGoogleApiClient.connect(); //Add this line!

    //................

为什么我的位置不在我的Android应用程序的onLocationChanged方法中注销？

1 个答案: