location_updated_message 无法解析或不是字段
location_updated_message cannot be resolved or is not a field
我一直在努力理解 android 开发者网站中提供的代码。
https://developer.android.com/training/location/receive-location-updates.html#stop-updates
这让我想到了这段 github 代码。
https://github.com/googlesamples/android-play-location/tree/master/LocationUpdates
所以我一直将其全部复制粘贴到我的应用程序中。使用我自己的 API 密钥等。但是我在 onLocationChanged 方法中遇到了这个错误，它强调了 location_updated_message.
错误是"location_updated_message cannot be resolved or is not a field. "我该怎么办？
package com.example.mappane;
import android.location.Location;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
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.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 java.text.DateFormat;
import java.util.Date;
/**
* Getting Location Updates.
*
* Demonstrates how to use the Fused Location Provider API to get updates about a device's
* location. The Fused Location Provider is part of the Google Play services location APIs.
*
* For a simpler example that shows the use of Google Play services to fetch the last known location
* of a device, see
* https://github.com/googlesamples/android-play-location/tree/master/BasicLocation.
*
* This sample uses Google Play services, but it does not require authentication. For a sample that
* uses Google Play services for authentication, see
* https://github.com/googlesamples/android-google-accounts/tree/master/QuickStart.
*/
public class MapActivity extends ActionBarActivity implements
ConnectionCallbacks, OnConnectionFailedListener, LocationListener {
protected static final String TAG = "location-updates-sample";
/**
* The desired interval for location updates. Inexact. Updates may be more or less frequent.
*/
public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
/**
* The fastest rate for active location updates. Exact. Updates will never be more frequent
* than this value.
*/
public static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS =
UPDATE_INTERVAL_IN_MILLISECONDS / 2;
// Keys for storing activity state in the Bundle.
protected final static String REQUESTING_LOCATION_UPDATES_KEY = "requesting-location-updates-key";
protected final static String LOCATION_KEY = "location-key";
protected final static String LAST_UPDATED_TIME_STRING_KEY = "last-updated-time-string-key";
/**
* Provides the entry point to Google Play services.
*/
protected GoogleApiClient mGoogleApiClient;
/**
* Stores parameters for requests to the FusedLocationProviderApi.
*/
protected LocationRequest mLocationRequest;
/**
* Represents a geographical location.
*/
protected Location mCurrentLocation;
// UI Widgets.
protected Button mStartUpdatesButton;
protected Button mStopUpdatesButton;
protected TextView mLastUpdateTimeTextView;
protected TextView mLatitudeTextView;
protected TextView mLongitudeTextView;
/**
* Tracks the status of the location updates request. Value changes when the user presses the
* Start Updates and Stop Updates buttons.
*/
protected Boolean mRequestingLocationUpdates;
/**
* Time when the location was updated represented as a String.
*/
protected String mLastUpdateTime;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
// Locate the UI widgets.
mStartUpdatesButton = (Button) findViewById(R.id.start_updates_button);
mStopUpdatesButton = (Button) findViewById(R.id.stop_updates_button);
mLatitudeTextView = (TextView) findViewById(R.id.latitude_text);
mLongitudeTextView = (TextView) findViewById(R.id.longitude_text);
mLastUpdateTimeTextView = (TextView) findViewById(R.id.last_update_time_text);
mRequestingLocationUpdates = false;
mLastUpdateTime = "";
// Update values using data stored in the Bundle.
updateValuesFromBundle(savedInstanceState);
// Kick off the process of building a GoogleApiClient and requesting the LocationServices
// API.
buildGoogleApiClient();
}
/**
* Updates fields based on data stored in the bundle.
*
* @param savedInstanceState The activity state saved in the Bundle.
*/
private void updateValuesFromBundle(Bundle savedInstanceState) {
Log.i(TAG, "Updating values from bundle");
if (savedInstanceState != null) {
// Update the value of mRequestingLocationUpdates from the Bundle, and make sure that
// the Start Updates and Stop Updates buttons are correctly enabled or disabled.
if (savedInstanceState.keySet().contains(REQUESTING_LOCATION_UPDATES_KEY)) {
mRequestingLocationUpdates = savedInstanceState.getBoolean(
REQUESTING_LOCATION_UPDATES_KEY);
setButtonsEnabledState();
}
// Update the value of mCurrentLocation from the Bundle and update the UI to show the
// correct latitude and longitude.
if (savedInstanceState.keySet().contains(LOCATION_KEY)) {
// Since LOCATION_KEY was found in the Bundle, we can be sure that mCurrentLocation
// is not null.
mCurrentLocation = savedInstanceState.getParcelable(LOCATION_KEY);
}
// Update the value of mLastUpdateTime from the Bundle and update the UI.
if (savedInstanceState.keySet().contains(LAST_UPDATED_TIME_STRING_KEY)) {
mLastUpdateTime = savedInstanceState.getString(LAST_UPDATED_TIME_STRING_KEY);
}
updateUI();
}
}
/**
* Builds a GoogleApiClient. Uses the {@code #addApi} method to request the
* LocationServices API.
*/
protected synchronized void buildGoogleApiClient() {
Log.i(TAG, "Building GoogleApiClient");
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
createLocationRequest();
}
/**
* Sets up the location request. Android has two location request settings:
* {@code ACCESS_COARSE_LOCATION} and {@code ACCESS_FINE_LOCATION}. These settings control
* the accuracy of the current location. This sample uses ACCESS_FINE_LOCATION, as defined in
* the AndroidManifest.xml.
* <p/>
* When the ACCESS_FINE_LOCATION setting is specified, combined with a fast update
* interval (5 seconds), the Fused Location Provider API returns location updates that are
* accurate to within a few feet.
* <p/>
* These settings are appropriate for mapping applications that show real-time location
* updates.
*/
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
// Sets the desired interval for active location updates. This interval is
// inexact. You may not receive updates at all if no location sources are available, or
// you may receive them slower than requested. You may also receive updates faster than
// requested if other applications are requesting location at a faster interval.
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
// Sets the fastest rate for active location updates. This interval is exact, and your
// application will never receive updates faster than this value.
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
/**
* Handles the Start Updates button and requests start of location updates. Does nothing if
* updates have already been requested.
*/
public void startUpdatesButtonHandler(View view) {
if (!mRequestingLocationUpdates) {
mRequestingLocationUpdates = true;
setButtonsEnabledState();
startLocationUpdates();
}
}
/**
* Handles the Stop Updates button, and requests removal of location updates. Does nothing if
* updates were not previously requested.
*/
public void stopUpdatesButtonHandler(View view) {
if (mRequestingLocationUpdates) {
mRequestingLocationUpdates = false;
setButtonsEnabledState();
stopLocationUpdates();
}
}
/**
* Requests location updates from the FusedLocationApi.
*/
protected void startLocationUpdates() {
// The final argument to {@code requestLocationUpdates()} is a LocationListener
// (http://developer.android.com/reference/com/google/android/gms/location/LocationListener.html).
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
/**
* Ensures that only one button is enabled at any time. The Start Updates button is enabled
* if the user is not requesting location updates. The Stop Updates button is enabled if the
* user is requesting location updates.
*/
private void setButtonsEnabledState() {
if (mRequestingLocationUpdates) {
mStartUpdatesButton.setEnabled(false);
mStopUpdatesButton.setEnabled(true);
} else {
mStartUpdatesButton.setEnabled(true);
mStopUpdatesButton.setEnabled(false);
}
}
/**
* Updates the latitude, the longitude, and the last location time in the UI.
*/
private void updateUI() {
mLatitudeTextView.setText(String.valueOf(mCurrentLocation.getLatitude()));
mLongitudeTextView.setText(String.valueOf(mCurrentLocation.getLongitude()));
mLastUpdateTimeTextView.setText(mLastUpdateTime);
}
/**
* Removes location updates from the FusedLocationApi.
*/
protected void stopLocationUpdates() {
// It is a good practice to remove location requests when the activity is in a paused or
// stopped state. Doing so helps battery performance and is especially
// recommended in applications that request frequent location updates.
// The final argument to {@code requestLocationUpdates()} is a LocationListener
// (http://developer.android.com/reference/com/google/android/gms/location/LocationListener.html).
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
@Override
protected void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
public void onResume() {
super.onResume();
// Within {@code onPause()}, we pause location updates, but leave the
// connection to GoogleApiClient intact. Here, we resume receiving
// location updates if the user has requested them.
if (mGoogleApiClient.isConnected() && mRequestingLocationUpdates) {
startLocationUpdates();
}
}
@Override
protected void onPause() {
super.onPause();
// Stop location updates to save battery, but don't disconnect the GoogleApiClient object.
stopLocationUpdates();
}
@Override
protected void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
/**
* Runs when a GoogleApiClient object successfully connects.
*/
@Override
public void onConnected(Bundle connectionHint) {
Log.i(TAG, "Connected to GoogleApiClient");
// If the initial location was never previously requested, we use
// FusedLocationApi.getLastLocation() to get it. If it was previously requested, we store
// its value in the Bundle and check for it in onCreate(). We
// do not request it again unless the user specifically requests location updates by pressing
// the Start Updates button.
//
// Because we cache the value of the initial location in the Bundle, it means that if the
// user launches the activity,
// moves to a new location, and then changes the device orientation, the original location
// is displayed as the activity is re-created.
if (mCurrentLocation == null) {
mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUI();
}
// If the user presses the Start Updates button before GoogleApiClient connects, we set
// mRequestingLocationUpdates to true (see startUpdatesButtonHandler()). Here, we check
// the value of mRequestingLocationUpdates and if it is true, we start location updates.
if (mRequestingLocationUpdates) {
startLocationUpdates();
}
}
/**
* Callback that fires when the location changes.
*/
@Override
public void onLocationChanged(Location location) {
mCurrentLocation = location;
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUI();
//THIS LINE
//LOCATION_UPDATED_MESSAGE is underlined
Toast.makeText(this, getResources().getString(R.string.location_updated_message),
Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionSuspended(int cause) {
// 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 result) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + result.getErrorCode());
}
/**
* Stores activity data in the Bundle.
*/
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putBoolean(REQUESTING_LOCATION_UPDATES_KEY, mRequestingLocationUpdates);
savedInstanceState.putParcelable(LOCATION_KEY, mCurrentLocation);
savedInstanceState.putString(LAST_UPDATED_TIME_STRING_KEY, mLastUpdateTime);
super.onSaveInstanceState(savedInstanceState);
}
}
这是 xml 文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="@dimen/layout_padding">
<TextView
android:id="@+id/latitude_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="74dp"
android:layout_marginTop="44dp"
android:text="TextView" />
<TextView
android:id="@+id/longitude_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="64dp"
android:text="TextView" />
<Button
android:id="@+id/start_updates_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/stop_updates_button"
android:layout_centerHorizontal="true"
android:layout_marginBottom="58dp"
android:text="start_updates_button" />
<Button
android:id="@+id/stop_updates_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/start_updates_button"
android:layout_alignParentBottom="true"
android:layout_marginBottom="85dp"
android:text="stop_updates_buttonn" />
<TextView
android:id="@+id/last_update_time_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="23dp"
android:layout_marginTop="16dp"
android:text="TextView" />
</RelativeLayout>
我猜你忘了放一个 strings.xml 资源文件，其中包含名为 location_updated_message 的字符串字符串资源（文件名无关紧要）
转到您的项目文件夹并搜索 res->values->strings.xml 然后添加
string name="location_updated_message"> 在此留言 />
我一直在努力理解 android 开发者网站中提供的代码。
https://developer.android.com/training/location/receive-location-updates.html#stop-updates
这让我想到了这段 github 代码。
https://github.com/googlesamples/android-play-location/tree/master/LocationUpdates
所以我一直将其全部复制粘贴到我的应用程序中。使用我自己的 API 密钥等。但是我在 onLocationChanged 方法中遇到了这个错误，它强调了 location_updated_message.
错误是"location_updated_message cannot be resolved or is not a field. "我该怎么办？
package com.example.mappane;
import android.location.Location;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
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.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 java.text.DateFormat;
import java.util.Date;
/**
* Getting Location Updates.
*
* Demonstrates how to use the Fused Location Provider API to get updates about a device's
* location. The Fused Location Provider is part of the Google Play services location APIs.
*
* For a simpler example that shows the use of Google Play services to fetch the last known location
* of a device, see
* https://github.com/googlesamples/android-play-location/tree/master/BasicLocation.
*
* This sample uses Google Play services, but it does not require authentication. For a sample that
* uses Google Play services for authentication, see
* https://github.com/googlesamples/android-google-accounts/tree/master/QuickStart.
*/
public class MapActivity extends ActionBarActivity implements
ConnectionCallbacks, OnConnectionFailedListener, LocationListener {
protected static final String TAG = "location-updates-sample";
/**
* The desired interval for location updates. Inexact. Updates may be more or less frequent.
*/
public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
/**
* The fastest rate for active location updates. Exact. Updates will never be more frequent
* than this value.
*/
public static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS =
UPDATE_INTERVAL_IN_MILLISECONDS / 2;
// Keys for storing activity state in the Bundle.
protected final static String REQUESTING_LOCATION_UPDATES_KEY = "requesting-location-updates-key";
protected final static String LOCATION_KEY = "location-key";
protected final static String LAST_UPDATED_TIME_STRING_KEY = "last-updated-time-string-key";
/**
* Provides the entry point to Google Play services.
*/
protected GoogleApiClient mGoogleApiClient;
/**
* Stores parameters for requests to the FusedLocationProviderApi.
*/
protected LocationRequest mLocationRequest;
/**
* Represents a geographical location.
*/
protected Location mCurrentLocation;
// UI Widgets.
protected Button mStartUpdatesButton;
protected Button mStopUpdatesButton;
protected TextView mLastUpdateTimeTextView;
protected TextView mLatitudeTextView;
protected TextView mLongitudeTextView;
/**
* Tracks the status of the location updates request. Value changes when the user presses the
* Start Updates and Stop Updates buttons.
*/
protected Boolean mRequestingLocationUpdates;
/**
* Time when the location was updated represented as a String.
*/
protected String mLastUpdateTime;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
// Locate the UI widgets.
mStartUpdatesButton = (Button) findViewById(R.id.start_updates_button);
mStopUpdatesButton = (Button) findViewById(R.id.stop_updates_button);
mLatitudeTextView = (TextView) findViewById(R.id.latitude_text);
mLongitudeTextView = (TextView) findViewById(R.id.longitude_text);
mLastUpdateTimeTextView = (TextView) findViewById(R.id.last_update_time_text);
mRequestingLocationUpdates = false;
mLastUpdateTime = "";
// Update values using data stored in the Bundle.
updateValuesFromBundle(savedInstanceState);
// Kick off the process of building a GoogleApiClient and requesting the LocationServices
// API.
buildGoogleApiClient();
}
/**
* Updates fields based on data stored in the bundle.
*
* @param savedInstanceState The activity state saved in the Bundle.
*/
private void updateValuesFromBundle(Bundle savedInstanceState) {
Log.i(TAG, "Updating values from bundle");
if (savedInstanceState != null) {
// Update the value of mRequestingLocationUpdates from the Bundle, and make sure that
// the Start Updates and Stop Updates buttons are correctly enabled or disabled.
if (savedInstanceState.keySet().contains(REQUESTING_LOCATION_UPDATES_KEY)) {
mRequestingLocationUpdates = savedInstanceState.getBoolean(
REQUESTING_LOCATION_UPDATES_KEY);
setButtonsEnabledState();
}
// Update the value of mCurrentLocation from the Bundle and update the UI to show the
// correct latitude and longitude.
if (savedInstanceState.keySet().contains(LOCATION_KEY)) {
// Since LOCATION_KEY was found in the Bundle, we can be sure that mCurrentLocation
// is not null.
mCurrentLocation = savedInstanceState.getParcelable(LOCATION_KEY);
}
// Update the value of mLastUpdateTime from the Bundle and update the UI.
if (savedInstanceState.keySet().contains(LAST_UPDATED_TIME_STRING_KEY)) {
mLastUpdateTime = savedInstanceState.getString(LAST_UPDATED_TIME_STRING_KEY);
}
updateUI();
}
}
/**
* Builds a GoogleApiClient. Uses the {@code #addApi} method to request the
* LocationServices API.
*/
protected synchronized void buildGoogleApiClient() {
Log.i(TAG, "Building GoogleApiClient");
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
createLocationRequest();
}
/**
* Sets up the location request. Android has two location request settings:
* {@code ACCESS_COARSE_LOCATION} and {@code ACCESS_FINE_LOCATION}. These settings control
* the accuracy of the current location. This sample uses ACCESS_FINE_LOCATION, as defined in
* the AndroidManifest.xml.
* <p/>
* When the ACCESS_FINE_LOCATION setting is specified, combined with a fast update
* interval (5 seconds), the Fused Location Provider API returns location updates that are
* accurate to within a few feet.
* <p/>
* These settings are appropriate for mapping applications that show real-time location
* updates.
*/
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
// Sets the desired interval for active location updates. This interval is
// inexact. You may not receive updates at all if no location sources are available, or
// you may receive them slower than requested. You may also receive updates faster than
// requested if other applications are requesting location at a faster interval.
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
// Sets the fastest rate for active location updates. This interval is exact, and your
// application will never receive updates faster than this value.
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
/**
* Handles the Start Updates button and requests start of location updates. Does nothing if
* updates have already been requested.
*/
public void startUpdatesButtonHandler(View view) {
if (!mRequestingLocationUpdates) {
mRequestingLocationUpdates = true;
setButtonsEnabledState();
startLocationUpdates();
}
}
/**
* Handles the Stop Updates button, and requests removal of location updates. Does nothing if
* updates were not previously requested.
*/
public void stopUpdatesButtonHandler(View view) {
if (mRequestingLocationUpdates) {
mRequestingLocationUpdates = false;
setButtonsEnabledState();
stopLocationUpdates();
}
}
/**
* Requests location updates from the FusedLocationApi.
*/
protected void startLocationUpdates() {
// The final argument to {@code requestLocationUpdates()} is a LocationListener
// (http://developer.android.com/reference/com/google/android/gms/location/LocationListener.html).
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
/**
* Ensures that only one button is enabled at any time. The Start Updates button is enabled
* if the user is not requesting location updates. The Stop Updates button is enabled if the
* user is requesting location updates.
*/
private void setButtonsEnabledState() {
if (mRequestingLocationUpdates) {
mStartUpdatesButton.setEnabled(false);
mStopUpdatesButton.setEnabled(true);
} else {
mStartUpdatesButton.setEnabled(true);
mStopUpdatesButton.setEnabled(false);
}
}
/**
* Updates the latitude, the longitude, and the last location time in the UI.
*/
private void updateUI() {
mLatitudeTextView.setText(String.valueOf(mCurrentLocation.getLatitude()));
mLongitudeTextView.setText(String.valueOf(mCurrentLocation.getLongitude()));
mLastUpdateTimeTextView.setText(mLastUpdateTime);
}
/**
* Removes location updates from the FusedLocationApi.
*/
protected void stopLocationUpdates() {
// It is a good practice to remove location requests when the activity is in a paused or
// stopped state. Doing so helps battery performance and is especially
// recommended in applications that request frequent location updates.
// The final argument to {@code requestLocationUpdates()} is a LocationListener
// (http://developer.android.com/reference/com/google/android/gms/location/LocationListener.html).
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
@Override
protected void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
public void onResume() {
super.onResume();
// Within {@code onPause()}, we pause location updates, but leave the
// connection to GoogleApiClient intact. Here, we resume receiving
// location updates if the user has requested them.
if (mGoogleApiClient.isConnected() && mRequestingLocationUpdates) {
startLocationUpdates();
}
}
@Override
protected void onPause() {
super.onPause();
// Stop location updates to save battery, but don't disconnect the GoogleApiClient object.
stopLocationUpdates();
}
@Override
protected void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
/**
* Runs when a GoogleApiClient object successfully connects.
*/
@Override
public void onConnected(Bundle connectionHint) {
Log.i(TAG, "Connected to GoogleApiClient");
// If the initial location was never previously requested, we use
// FusedLocationApi.getLastLocation() to get it. If it was previously requested, we store
// its value in the Bundle and check for it in onCreate(). We
// do not request it again unless the user specifically requests location updates by pressing
// the Start Updates button.
//
// Because we cache the value of the initial location in the Bundle, it means that if the
// user launches the activity,
// moves to a new location, and then changes the device orientation, the original location
// is displayed as the activity is re-created.
if (mCurrentLocation == null) {
mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUI();
}
// If the user presses the Start Updates button before GoogleApiClient connects, we set
// mRequestingLocationUpdates to true (see startUpdatesButtonHandler()). Here, we check
// the value of mRequestingLocationUpdates and if it is true, we start location updates.
if (mRequestingLocationUpdates) {
startLocationUpdates();
}
}
/**
* Callback that fires when the location changes.
*/
@Override
public void onLocationChanged(Location location) {
mCurrentLocation = location;
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUI();
//THIS LINE
//LOCATION_UPDATED_MESSAGE is underlined
Toast.makeText(this, getResources().getString(R.string.location_updated_message),
Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionSuspended(int cause) {
// 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 result) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + result.getErrorCode());
}
/**
* Stores activity data in the Bundle.
*/
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putBoolean(REQUESTING_LOCATION_UPDATES_KEY, mRequestingLocationUpdates);
savedInstanceState.putParcelable(LOCATION_KEY, mCurrentLocation);
savedInstanceState.putString(LAST_UPDATED_TIME_STRING_KEY, mLastUpdateTime);
super.onSaveInstanceState(savedInstanceState);
}
}
这是 xml 文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="@dimen/layout_padding">
<TextView
android:id="@+id/latitude_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="74dp"
android:layout_marginTop="44dp"
android:text="TextView" />
<TextView
android:id="@+id/longitude_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="64dp"
android:text="TextView" />
<Button
android:id="@+id/start_updates_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/stop_updates_button"
android:layout_centerHorizontal="true"
android:layout_marginBottom="58dp"
android:text="start_updates_button" />
<Button
android:id="@+id/stop_updates_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/start_updates_button"
android:layout_alignParentBottom="true"
android:layout_marginBottom="85dp"
android:text="stop_updates_buttonn" />
<TextView
android:id="@+id/last_update_time_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="23dp"
android:layout_marginTop="16dp"
android:text="TextView" />
</RelativeLayout>
我猜你忘了放一个 strings.xml 资源文件，其中包含名为 location_updated_message 的字符串字符串资源（文件名无关紧要）
转到您的项目文件夹并搜索 res->values->strings.xml 然后添加 string name="location_updated_message"> 在此留言 />