Question

我正在创建一个应用程序，可以访问并使用用户的经度和经度来显示附近的餐馆。

我试图从onConnected（Bundle bunle）方法中检索纬度和经度变量，如下所示，以便在onCreate（）方法中访问和使用它们，但我在顶部声明的String纬度不会存储当我将其设置为等于onConnnected（）方法上的用户纬度时的纬度值。我尝试测试当我在Toast消息上显示String时结果是什么，但是toast只是空白，表明该字符串未设置为等于纬度值。但是，如果我尝试在onConnected（）方法的范围内显示toast，它就可以工作。但我真的需要在onCreate（）方法的onConnected（）方法之外访问这个纬度和经度。

我已经发布了下面的代码！任何帮助将不胜感激！

    public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener, GoogleApiClient.ConnectionCallbacks, com.google.android.gms.location.LocationListener {

protected static final String TAG = "Gokul Log Message: ";
protected GoogleApiClient mGoogleApiClient;
protected Location mLastLocation;
protected TextView textLatitude;
public String mLat = null;

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

    textLatitude = (TextView)this.findViewById(R.id.textLatitude);

    Toast.makeText(MainActivity.this, mLat, Toast.LENGTH_LONG).show();

    buildGoogleApiClient();

}

protected synchronized void buildGoogleApiClient(){
    Log.v("Log1", "Entering buildGoogleApiClient method");

    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
}
@Override
protected void onStart(){
    Log.v("Log1", "Entering onStart() method");

    super.onStart();
    mGoogleApiClient.connect();
}
@Override
protected void onStop(){
    Log.v("Log1", "Entering onStop() method");

    super.onStop();
    if (mGoogleApiClient.isConnected()){
        mGoogleApiClient.disconnect();
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onConnected(Bundle bundle) {
    Log.v("Log1", "Entering onConnected() method");


    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null){
        textLatitude.setText(String.valueOf(mLastLocation.getLatitude()));
       //textLongitude.setText(String.valueOf(mLastLocation.getLongitude()));
        mLat = String.valueOf(mLastLocation.getLatitude());
        Log.v("Log1onConnected", mLat + "asd");
    }

    Log.v("Log1onConnected2", mLat + "asd");

}

@Override
public void onConnectionSuspended(int i) {


    Log.i(TAG, "Connection suspended");
    mGoogleApiClient.connect();

}

@Override
public void onLocationChanged(Location location) {

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {

    Log.i(TAG, "Connection failed: " + connectionResult.getErrorCode());

}

}

Answer 1

它没有改变，因为它还没有位置。仅仅因为你连接谷歌播放并不意味着一个位置准备好了。您需要侦听位置更新并在onLocationChanged中设置值。

访问纬度和经度Android Google API

1 个答案: