我想在启用GPS时在谷歌地图上设置标记。
我创建了一个广播接收器来检查GPS是否启用或禁用。它的工作原理。但是，我不知道如何使用Google Play服务获取位置并在地图上设置标记。
LocationClient上的connect()方法在onStart()方法上启动，startuupdates()方法在onResume()方法上启动。
如何在广播接收器上设置地图?
如果我使用getLocation()(见下文)，它返回null，因为我没有连接到GooglePlay服务。
如果我使用LocationClient.connect()，我必须等待客户端连接到获取位置。
我该怎么做呢?
PS:我使用这个示例代码连接到Google play服务:http://developer.android.com/training/location/receive-location-updates.html
我的内部类GpsLocationReceiver:
public class GpsLocationReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
LocationManager lm = (LocationManager) context.getSystemService(Service.LOCATION_SERVICE);
boolean isEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
onGpsStatusChanged(isEnabled);
}
}
private void onGpsStatusChanged(boolean b) {
if (!servicesConnected() && b) {
mLocationClient.connect();
}
/*currentLocation = getLocation();
//setUpMapIfNeeded();
if (currentLocation == null) {
Toast.makeText(this, "GPS enabled - " + b + " Loc : null", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "GPS enabled - " + b + " Loc : " + currentLocation.toString(), Toast.LENGTH_LONG).show();
}*/
}
方法getLocation
public Location getLocation() {
// If Google Play Services is available
if (servicesConnected()) {
// Get the current location
return mLocationClient.getLastLocation();
}
return null;
}
my method onConnected():
@Override
public void onConnected(Bundle bundle) {
//Set currentLocation
currentLocation = getLocation();
if (currentLocation == null) {
Toast.makeText(HomeActivity.this, "location null", Toast.LENGTH_LONG).show();
}
else {
Toast.makeText(HomeActivity.this, "Lat : "+ currentLocation.getLatitude() + " Long : "+currentLocation.getLongitude(), Toast.LENGTH_LONG).show();
//Get map if needed
setUpMapIfNeeded();
}
if (mUpdatesRequested) {
startPeriodicUpdates();
}
}
Thx
编辑:我修改了我的代码。对我来说似乎更清楚了。现在，我的函数getLocation()在连接成功完成后调用，返回null。这意味着google play服务不可用。
如果我理解得很好，问题是即使GPS启用了，你也必须等到GPS获得至少它的第一个修复才能获得用户的位置。我不明白为什么你要检查BroadcastReceiver中的GPS状态，但我认为如果你在连接LocationClient之前检查GPS是否启用(也许你可以在启动Actviity之前检查它，如果你的要求允许的话)，然后你可以请求位置。
现在，还有另一个问题:如果您调用mLocationClient.getLastLocation()，则有可能检索缓存位置(称为系统注册的"最后一个位置")，或者如果系统没有缓存位置，则可以获得null位置，因此您的标记显然是不准确的。我通常做,检查后如果你可以启用GPS LocationRequest PRIORITY_HIGH_ACCURACY和实现LocationListener安卓培训,之后第一个收到locationChange可以removeLocationUpdates如果你只想要一个标记现在可以肯定的是,位置是用户的当前位置,但你必须不可避免地等待GPS连接,可能是几分钟或者它可能永远不会发生,这取决于天气和一些你无法控制的随机变量。
编辑:这是一个来自Google Play Services SDK样本的例子(SDK/extras/Google/google_play_services/samples/maps)::
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.mapdemo;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient.ConnectionCallbacks;
import com.google.android.gms.common.GooglePlayServicesClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMyLocationButtonClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
/**
* This demo shows how GMS Location can be used to check for changes to the users location. The
* "My Location" button uses GMS Location to set the blue dot representing the users location. To
* track changes to the users location on the map, we request updates from the
* {@link LocationClient}.
*/
public class MyLocationDemoActivity extends FragmentActivity
implements
ConnectionCallbacks,
OnConnectionFailedListener,
LocationListener,
OnMyLocationButtonClickListener {
private GoogleMap mMap;
private LocationClient mLocationClient;
private TextView mMessageView;
// These settings are the same as the settings for the map. They will in fact give you updates
// at the maximal rates currently possible.
private static final LocationRequest REQUEST = LocationRequest.create()
.setInterval(5000) // 5 seconds
.setFastestInterval(16) // 16ms = 60fps
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_location_demo);
mMessageView = (TextView) findViewById(R.id.message_text);
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
setUpLocationClientIfNeeded();
mLocationClient.connect();
}
@Override
public void onPause() {
super.onPause();
if (mLocationClient != null) {
mLocationClient.disconnect();
}
}
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) {
mMap.setMyLocationEnabled(true);
mMap.setOnMyLocationButtonClickListener(this);
}
}
}
private void setUpLocationClientIfNeeded() {
if (mLocationClient == null) {
mLocationClient = new LocationClient(
getApplicationContext(),
this, // ConnectionCallbacks
this); // OnConnectionFailedListener
}
}
/**
* Button to get current Location. This demonstrates how to get the current Location as required
* without needing to register a LocationListener.
*/
public void showMyLocation(View view) {
if (mLocationClient != null && mLocationClient.isConnected()) {
String msg = "Location = " + mLocationClient.getLastLocation();
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_SHORT).show();
}
}
/**
* Implementation of {@link LocationListener}.
*/
@Override
public void onLocationChanged(Location location) {
mMessageView.setText("Location = " + location);
}
/**
* Callback called when connected to GCore. Implementation of {@link ConnectionCallbacks}.
*/
@Override
public void onConnected(Bundle connectionHint) {
mLocationClient.requestLocationUpdates(
REQUEST,
this); // LocationListener
}
/**
* Callback called when disconnected from GCore. Implementation of {@link ConnectionCallbacks}.
*/
@Override
public void onDisconnected() {
// Do nothing
}
/**
* Implementation of {@link OnConnectionFailedListener}.
*/
@Override
public void onConnectionFailed(ConnectionResult result) {
// Do nothing
}
@Override
public boolean onMyLocationButtonClick() {
Toast.makeText(this, "MyLocation button clicked", Toast.LENGTH_SHORT).show();
// Return false so that we don't consume the event and the default behavior still occurs
// (the camera animates to the user's current position).
return false;
}
}
这个答案怎么样?使用地理定位，并为清单提供精细位置访问
https://stackoverflow.com/a/8543819/2931489Voggela教程http://www.vogella.com/tutorials/AndroidLocationAPI/article.html