所有。我正在写一个关于GPS位置的Android应用程序。
我在模拟器上尝试过并手动输入纬度和经度，它工作正常。 但是，我的问题是：在真实设备上，在调试模式下，只有在改变位置时才能通过使用意图去下一个类。如果我直接启动应用程序，我可以看到闪烁的GPS图标，但应用程序将只停留在此处，并且不会启动下一个活动。似乎永远不会改变onLocationChanged（）中的变量。
我听说过立即获取位置是使用getLastKnownLocation（）方法。但我没能到达应该使用它的地方。
这是我使用LocationManager获取位置的类。
有什么解决方案吗？我很困惑。非常感谢!!
public class mainMenu extends Activity{
private LocationManager locationManager = null;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1 = (Button)findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener(){
public void onClick(View v){
Intent i3 = new Intent();
i3.setClass(mainMenu.this, police.class);
i3.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mainMenu.this.startActivityForResult(i3,0);
}
});
Button button2 = (Button)findViewById(R.id.button2);
button2.setOnClickListener(new OnClickListener(){
public void onClick(View v){
Intent i3 = new Intent();
i3.setClass(mainMenu.this, ambulance.class);
i3.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mainMenu.this.startActivityForResult(i3,0);
}
});
Button button3 = (Button)findViewById(R.id.button3);
button3.setOnClickListener(new OnClickListener(){
public void onClick(View v){
Intent i3 = new Intent();
i3.setClass(mainMenu.this, fire_station.class);
i3.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mainMenu.this.startActivityForResult(i3,0);
}
});
locationManager = (LocationManager)mainMenu.this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 120000 , 0, new MyLocationUpdater());
String provider = LocationManager.GPS_PROVIDER;
Location location = locationManager.getLastKnownLocation(provider);
}
public class MyLocationUpdater implements LocationListener{ //change location interface
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
// store the location data
// get the best record
Double lat = location.getLatitude();
Double lon = location.getLongitude();
System.out.println("The latitude is " + lat + "and "
+ "the longitude is "+ lon);
Double lat11 = lat - 1/69.0;
Double lat12 = lat + 1/69.0;
Double lon11 = lon - 1/42.0;
Double lon12 = lon + 1/42.0;
StaticVariables.latS1 = lat11.toString();
StaticVariables.latN1 = lat12.toString();
StaticVariables.lonW1 = lon11.toString();
StaticVariables.lonE1 = lon12.toString();
Double lat111 = lat - 2/69.0;
Double lat121 = lat + 2/69.0;
Double lon111 = lon - 2/42.0;
Double lon121 = lon + 2/42.0;
StaticVariables.latS11 = lat111.toString();
StaticVariables.latN11 = lat121.toString();
StaticVariables.lonW11 = lon111.toString();
StaticVariables.lonE11 = lon121.toString();
// ==================================================
// ambulances
Double lat21 = lat - 3/69.0;
Double lat22 = lat + 3/69.0;
Double lon21 = lon - 3/42.0;
Double lon22 = lon + 3/42.0;
StaticVariables.latS2 = lat21.toString();
StaticVariables.latN2 = lat22.toString();
StaticVariables.lonW2 = lon21.toString();
StaticVariables.lonE2 = lon22.toString();
Double lat211 = lat - 5.5/69.0;
Double lat221 = lat + 5.5/69.0;
Double lon211 = lon - 5.5/42.0;
Double lon221 = lon + 5.5/42.0;
StaticVariables.latS21 = lat211.toString();
StaticVariables.latN21 = lat221.toString();
StaticVariables.lonW21 = lon211.toString();
StaticVariables.lonE21 = lon221.toString();
// ===================================================
// fire stations
Double lat31 = lat - 2/69.0;
Double lat32 = lat + 2/69.0;
Double lon31 = lon - 2/42.0;
Double lon32 = lon + 2/42.0;
StaticVariables.latS3 = lat31.toString();
StaticVariables.latN3 = lat32.toString();
StaticVariables.lonW3 = lon31.toString();
StaticVariables.lonE3 = lon32.toString();
Double lat311 = lat - 2/69.0;
Double lat321 = lat + 2/69.0;
Double lon311 = lon - 2/42.0;
Double lon321 = lon + 2/42.0;
StaticVariables.latS31 = lat311.toString();
StaticVariables.latN31 = lat321.toString();
StaticVariables.lonW31 = lon311.toString();
StaticVariables.lonE31 = lon321.toString();
Intent intent = new Intent();
intent.setClass(mainMenu.this, getPhoneNumber.class);
mainMenu.this.startActivity(intent);
}
@Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
}
}
答案 0 :(得分：3)
getLastKnownLocation方法不会触发onLocationChanged事件。重构代码的一种方法是将作用于Location的逻辑移动到单独的方法，然后在调用getLastKnownLocation之后以及从onLocationChanged方法调用该方法。
请注意，无法保证getLastKnownLocation会提供有意义的Location，因为自上次更新位置后设备可能已移动。
示例代码：
public void onCreate(Bundle savedInstanceState){
....
String provider = LocationManager.GPS_PROVIDER;
Location location = locationManager.getLastKnownLocation(provider);
updateLocation(location);
}
public class MyLocationUpdater implements LocationListener{ //change location interface
@Override
public void onLocationChanged(Location location) {
updateLocation(location);
}
...
}
void updateLocation(Location location) {
Double lat = location.getLatitude();
Double lon = location.getLongitude();
// the rest of the code from onLocationChanged
}
答案 1 :(得分：0)
getLastKnownLocation（）速度更快。这是第一次，它将返回null，或者没有值，直到没有建立连接。 您可以添加GpsListener以了解何时获取位置。搜索“如何获得gps修复”，您可能会回答您的问题
答案 2 :(得分：0)
我之前遇到同样的问题..但我有解决方案..这是立即获取位置的最简单方法。
public class LocationFinder extends Activity {
TextView textView1;
Location currentLocation;
double currentLatitude,currentLongitude;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textView1 = (TextView) findViewById(R.id.textView1);
Log.i("@@@@@@@@@@ Inside LocationFinder onCreate", "LocationFinder onCreate");
FindLocation();
}
public void FindLocation() {
LocationManager locationManager = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateLocation(location);
Toast.makeText(
LocationFinder.this,
String.valueOf(currentLatitude) + "\n"
+ String.valueOf(currentLongitude), 5000)
.show();
}
public void onStatusChanged(String provider, int status,
Bundle extras) {
}
public void onProviderEnabled(String provider) {
}
public void onProviderDisabled(String provider) {
}
};
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
}
void updateLocation(Location location) {
currentLocation = location;
currentLatitude = currentLocation.getLatitude();
currentLongitude = currentLocation.getLongitude();
textView1.setText(String.valueOf(currentLatitude) + "\n"
+ String.valueOf(currentLongitude));
}
}
不要忘记在Manifeast中给予许可。
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"/>
答案 3 :(得分：-1)
public class HomeActivity extends Activity implements LocationListener{
public static Context mContext;
private double latitude, longitude;
public LocationManager mLocManager;
// *******This is the new Code start on 11/4/2011 at 3 o'clock
/**
* This is the Home Button if user Login then it is move to TennisAppActivity otherwise move to Login
*
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
mContext=this;
super.onCreate(savedInstanceState);
setContentView(R.layout.homelayout);
mLocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
mLocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
this);
mLocManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0,
0, this);
locationUpdate();
((Button) this.findViewById(R.id.ButtonHome))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
startActivity(new Intent(HomeActivity.this,
DefaultDisplay.class));
}
});
((Button) this.findViewById(R.id.ButtonProfile))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if (GUIStatics.boolLoginStatus) {
startActivity(new Intent(HomeActivity.this,
MyProfile.class));
} else {
Intent intent=new Intent(HomeActivity.this,
Login.class);
intent.putExtra("moveTo","MyProfile");
startActivity(intent);
}
}
});
((Button) this.findViewById(R.id.ButtonNotifications))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if (GUIStatics.boolLoginStatus) {
startActivity(new Intent(HomeActivity.this,
ShowAllNotificationActiviry.class));
} else {
Intent intent=new Intent(HomeActivity.this,
Login.class);
intent.putExtra("moveTo","ShowAllNotificationActiviry");
startActivity(intent);
}
}
});
((Button) this.findViewById(R.id.ButtonFavorites))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if (GUIStatics.boolLoginStatus) {
startActivity(new Intent(HomeActivity.this,
FavoritesActivity.class));
} else {
Intent intent=new Intent(HomeActivity.this,
Login.class);
intent.putExtra("moveTo","FavoritesActivity");
startActivity(intent);
}
}
});
((Button) this.findViewById(R.id.ButtonMore))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
startActivity(new Intent(HomeActivity.this,
MoreListActivity.class));
}
});
}
public void locationUpdate()
{
CellLocation.requestLocationUpdate();
}
public void getAddress(double lat, double lng) {
Geocoder geocoder = new Geocoder(HomeActivity.mContext, Locale.getDefault());
try {
List<Address> addresses = geocoder.getFromLocation(lat, lng, 1);
Address obj = addresses.get(0);
String add = obj.getAddressLine(0);
GUIStatics.currentAddress = obj.getSubAdminArea() + ","
+ obj.getAdminArea();
GUIStatics.latitude = obj.getLatitude();
GUIStatics.longitude = obj.getLongitude();
GUIStatics.currentCity= obj.getSubAdminArea();
GUIStatics.currentState= obj.getAdminArea();
add = add + "\n" + obj.getCountryName();
add = add + "\n" + obj.getCountryCode();
add = add + "\n" + obj.getAdminArea();
add = add + "\n" + obj.getPostalCode();
add = add + "\n" + obj.getSubAdminArea();
add = add + "\n" + obj.getLocality();
add = add + "\n" + obj.getSubThoroughfare();
Log.v("IGA", "Address" + add);
// Toast.makeText(this, "Address=>" + add,
// Toast.LENGTH_SHORT).show();
// TennisAppActivity.showDialog(add);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
public void onLocationChanged(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
GUIStatics.latitude=location.getLatitude();
GUIStatics.longitude= location.getLongitude();
Log.v("Test", "IGA" + "Lat" + latitude + " Lng" + longitude);
//mLocManager.r
getAddress(latitude, longitude);
if(location!=null)
{
mLocManager.removeUpdates(this);
}
// Toast.makeText(this, "Lat" + latitude + " Lng" + longitude,
// Toast.LENGTH_SHORT).show();
}
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
Toast.makeText(HomeActivity.this, "Gps Disabled", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(
android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
if(arg1 ==
LocationProvider.TEMPORARILY_UNAVAILABLE) {
Toast.makeText(HomeActivity.this,
"LocationProvider.TEMPORARILY_UNAVAILABLE",
Toast.LENGTH_SHORT).show();
}
else if(arg1== LocationProvider.OUT_OF_SERVICE) {
Toast.makeText(HomeActivity.this,
"LocationProvider.OUT_OF_SERVICE", Toast.LENGTH_SHORT).show();
}
}
}
这是我用它来查找借助纬度和经度的设备位置的代码，我们还在此代码中调用了getLastLocationUpdate。 我希望这对你很有帮助。