我是android编程的初学者然后抱歉，如果这个问题看似愚蠢但我需要了解如何从类中更新视图，它不是活动或片段。我创建了一个从Google Play服务API获取数据的类。我需要将这些数据重定向到片段。哪些是实现它的常见软件设计模式？
这是代码，但不幸的是它没有工作
TodayFragment
package com.salvo.weather.android.fragment;
import android.os.Bundle;
import android.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.salvo.weather.android.R;
import com.salvo.weather.android.app.VolleyCallback;
import com.salvo.weather.android.entity.CurrentWeatherEntity;
import com.salvo.weather.android.geolocation.CurrentGeolocation;
/**
* A simple {@link Fragment} subclass.
*/
public class TodayFragment extends Fragment {
private static final String TAG = TodayFragment.class.getSimpleName();
private CurrentGeolocation mCurrentGeolocation;
public TodayFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_today, container, false);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCurrentGeolocation = CurrentGeolocation.get(getActivity());
}
@Override
public void onStart() {
super.onStart();
mCurrentGeolocation.getmGoogleApiClient().connect();
renderView();
}
@Override
public void onPause() {
super.onPause();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.stopLocationUpdates();
}
}
@Override
public void onResume() {
super.onResume();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.startLocationUpdates();
}
}
@Override
public void onStop() {
super.onStop();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.stopLocationUpdates();
}
}
public void renderView() {
// check if googleApiClient is connected
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.getmCurrentWeatherRequest().loadData(new VolleyCallback() {
@Override
public void onSuccess(CurrentWeatherEntity currentWeatherEntity) {
Log.i(TAG, currentWeatherEntity.getmCity());
}
});
}
}
}
CurrentGeolocation
package com.salvo.weather.android.geolocation;
import android.content.Context;
import android.location.Location;
import android.os.Bundle;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.salvo.weather.android.app.VolleyCallback;
import com.salvo.weather.android.client.request.CurrentWeatherRequest;
import com.salvo.weather.android.entity.CurrentGeolocationEntity;
import com.salvo.weather.android.entity.CurrentWeatherEntity;
/**
* Created by mazzy on 30/05/15.
*/
public class CurrentGeolocation
implements ConnectionCallbacks, OnConnectionFailedListener, LocationListener {
private static final String TAG = CurrentGeolocation.class.getSimpleName();
// SETTING CONSTANTS FOR THE LOCATION
private static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000; //ms
private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS = UPDATE_INTERVAL_IN_MILLISECONDS / 2;
private static CurrentGeolocation sCurrentGeolocation;
private boolean mRequestingLocationUpdates;
private Context mAppContext;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
private CurrentGeolocationEntity mCurrentGeolocationEntity;
private CurrentWeatherRequest mCurrentWeatherRequest;
public static CurrentGeolocation get(Context appContext) {
if (sCurrentGeolocation == null) {
sCurrentGeolocation = new CurrentGeolocation(appContext.getApplicationContext());
}
return sCurrentGeolocation;
}
private CurrentGeolocation(Context appContext) {
mAppContext = appContext;
mRequestingLocationUpdates = true;
mCurrentGeolocationEntity = new CurrentGeolocationEntity();
mCurrentWeatherRequest = CurrentWeatherRequest.get(appContext);
buildGoogleApiClient();
}
@Override
public void onConnected(Bundle bundle) {
Log.i(TAG, "Connected to GoggleApiClient");
if (mCurrentGeolocationEntity.getmLastLocation() == null) {
mCurrentGeolocationEntity.setmLastLocation(LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient));
mCurrentWeatherRequest.setmCurrentGeolocationEntity(mCurrentGeolocationEntity);
}
if (mRequestingLocationUpdates) {
startLocationUpdates();
}
}
@Override
public void onConnectionSuspended(int i) {
// The connection to Google Play services was lost for some reason. We call connect() to
// attempt to re-establish the connection.
Log.i(TAG, "Connection suspended");
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: error " + connectionResult.getErrorCode());
}
@Override
public void onLocationChanged(Location location) {
// update the location
mCurrentGeolocationEntity.setmLastLocation(location);
}
public GoogleApiClient getmGoogleApiClient() {
return mGoogleApiClient;
}
public void startLocationUpdates() {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
public void stopLocationUpdates() {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
public CurrentWeatherRequest getmCurrentWeatherRequest() {
return mCurrentWeatherRequest;
}
private synchronized void buildGoogleApiClient() {
Log.i(TAG, "Building Google Api Client");
mGoogleApiClient = new GoogleApiClient.Builder(mAppContext)
.addConnectionCallbacks(this)
.addApi(LocationServices.API)
.build();
createLocationRequest();
}
private void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
}
答案 0 :(得分：3)
您必须创建Listener。
package com.salvo.weather.android.fragment;
import android.os.Bundle;
import android.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.salvo.weather.android.R;
import com.salvo.weather.android.app.VolleyCallback;
import com.salvo.weather.android.entity.CurrentWeatherEntity;
import com.salvo.weather.android.geolocation.CurrentGeolocation;
/**
* A simple {@link Fragment} subclass.
*/
public class TodayFragment extends Fragment implements CurrentGeoloaction.OnUpdateListener {
private static final String TAG = TodayFragment.class.getSimpleName();
private CurrentGeolocation mCurrentGeolocation;
public TodayFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_today, container, false);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCurrentGeolocation = CurrentGeolocation.get(getActivity());
mCurrentGeolocation.setOnUpdateListener(this);
}
@Override
public void onStart() {
super.onStart();
mCurrentGeolocation.getmGoogleApiClient().connect();
renderView();
}
@Override
public void onPause() {
super.onPause();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.stopLocationUpdates();
}
}
@Override
public void onResume() {
super.onResume();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.startLocationUpdates();
}
}
@Override
public void onStop() {
super.onStop();
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.stopLocationUpdates();
}
}
@Override
public void onUpdate() {
renderView();
}
public void renderView() {
// check if googleApiClient is connected
if (mCurrentGeolocation.getmGoogleApiClient().isConnected()) {
mCurrentGeolocation.getmCurrentWeatherRequest().loadData(new VolleyCallback() {
@Override
public void onSuccess(CurrentWeatherEntity currentWeatherEntity) {
Log.i(TAG, currentWeatherEntity.getmCity());
}
});
}
}
}
package com.salvo.weather.android.geolocation;
import android.content.Context;
import android.location.Location;
import android.os.Bundle;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.salvo.weather.android.app.VolleyCallback;
import com.salvo.weather.android.client.request.CurrentWeatherRequest;
import com.salvo.weather.android.entity.CurrentGeolocationEntity;
import com.salvo.weather.android.entity.CurrentWeatherEntity;
/**
* Created by mazzy on 30/05/15.
*/
public class CurrentGeolocation
implements ConnectionCallbacks, OnConnectionFailedListener, LocationListener {
private static final String TAG = CurrentGeolocation.class.getSimpleName();
// SETTING CONSTANTS FOR THE LOCATION
private static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000; //ms
private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS = UPDATE_INTERVAL_IN_MILLISECONDS / 2;
private static CurrentGeolocation sCurrentGeolocation;
private boolean mRequestingLocationUpdates;
private Context mAppContext;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
private CurrentGeolocationEntity mCurrentGeolocationEntity;
private CurrentWeatherRequest mCurrentWeatherRequest;
private OnUpdateListener mOnUpdateListener;
public interface OnUpdateListener {
public void onUpdate();
}
public void setOnUpdateListener(Fragment todayFragment) {
this.mOnUpdateListener = (OnUpdateListener) todayFragment;
}
public static CurrentGeolocation get(Context appContext) {
if (sCurrentGeolocation == null) {
sCurrentGeolocation = new CurrentGeolocation(appContext.getApplicationContext());
}
return sCurrentGeolocation;
}
private CurrentGeolocation(Context appContext) {
mAppContext = appContext;
mRequestingLocationUpdates = true;
mCurrentGeolocationEntity = new CurrentGeolocationEntity();
mCurrentWeatherRequest = CurrentWeatherRequest.get(appContext);
buildGoogleApiClient();
}
@Override
public void onConnected(Bundle bundle) {
Log.i(TAG, "Connected to GoggleApiClient");
if (mCurrentGeolocationEntity.getmLastLocation() == null) {
mCurrentGeolocationEntity.setmLastLocation(LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient));
mCurrentWeatherRequest.setmCurrentGeolocationEntity(mCurrentGeolocationEntity);
}
if (mRequestingLocationUpdates) {
startLocationUpdates();
mOnUpdateListener.onUpdate();
}
}
@Override
public void onConnectionSuspended(int i) {
// The connection to Google Play services was lost for some reason. We call connect() to
// attempt to re-establish the connection.
Log.i(TAG, "Connection suspended");
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: error " + connectionResult.getErrorCode());
}
@Override
public void onLocationChanged(Location location) {
// update the location
mCurrentGeolocationEntity.setmLastLocation(location);
}
public GoogleApiClient getmGoogleApiClient() {
return mGoogleApiClient;
}
public void startLocationUpdates() {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
public void stopLocationUpdates() {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
public CurrentWeatherRequest getmCurrentWeatherRequest() {
return mCurrentWeatherRequest;
}
private synchronized void buildGoogleApiClient() {
Log.i(TAG, "Building Google Api Client");
mGoogleApiClient = new GoogleApiClient.Builder(mAppContext)
.addConnectionCallbacks(this)
.addApi(LocationServices.API)
.build();
createLocationRequest();
}
private void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
}