如何從我的android設備獲取當前的經度和緯度

Question

我正在使用此代碼，但在經度和緯度中爲null。

LocationManager lm =（LocationManager）getSystemService（Context.LOCATION_SERVICE）;
位置位置= lm.getLastKnownLocation（LocationManager.GPS_PROVIDER）;

請幫我

謝謝

Answer 1

可以使用的LocationManager。見例如：

LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
double longitude = location.getLongitude(); 
double latitude = location.getLatitude(); 

並將其放置在Manisfest：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 

Answer 2

看看這個教程：A Deep Dive Into Location

基本上，如果你想用最後已知得到的大致位置位置，你應該循環遍歷所有可能的提供者，像這樣的循環：

List<String> matchingProviders = locationManager.getAllProviders(); 
for (String provider: matchingProviders) { 
    Location location = locationManager.getLastKnownLocation(provider); 
    if (location != null) { 
    float accuracy = location.getAccuracy(); 
    long time = location.getTime(); 

    if ((time > minTime && accuracy < bestAccuracy)) { 
     bestResult = location; 
     bestAccuracy = accuracy; 
     bestTime = time; 
    } 
    else if (time < minTime && 
      bestAccuracy == Float.MAX_VALUE && time > bestTime){ 
     bestResult = location; 
     bestTime = time; 
    } 
    } 
} 

Answer 3

沒有你添加

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 

權限清單文件

Answer 4

Try This 

public class LocationDemo extends Activity implements LocationListener { 
private static final String TAG = "LocationDemo"; 
private static final String[] S = { "Out of Service", 
     "Temporarily Unavailable", "Available" }; 

private TextView output; 
private LocationManager locationManager; 
private String bestProvider; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    // Get the output UI 
    output = (TextView) findViewById(R.id.output); 

    // Get the location manager 
    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE); 

    // List all providers: 
    List<String> providers = locationManager.getAllProviders(); 
    for (String provider : providers) { 
     printProvider(provider); 
    } 

    Criteria criteria = new Criteria(); 
    bestProvider = locationManager.getBestProvider(criteria, false); 
    output.append("\n\nBEST Provider:\n"); 
    printProvider(bestProvider); 

    output.append("\n\nLocations (starting with last known):"); 
    Location location = locationManager.getLastKnownLocation(bestProvider); 
    printLocation(location); 
} 

/** Register for the updates when Activity is in foreground */ 
@Override 
protected void onResume() { 
    super.onResume(); 
    locationManager.requestLocationUpdates(bestProvider, 20000, 1, this); 
} 

/** Stop the updates when Activity is paused */ 
@Override 
protected void onPause() { 
    super.onPause(); 
    locationManager.removeUpdates(this); 
} 

public void onLocationChanged(Location location) { 
    printLocation(location); 
} 

public void onProviderDisabled(String provider) { 
    // let okProvider be bestProvider 
    // re-register for updates 
    output.append("\n\nProvider Disabled: " + provider); 
} 

public void onProviderEnabled(String provider) { 
    // is provider better than bestProvider? 
    // is yes, bestProvider = provider 
    output.append("\n\nProvider Enabled: " + provider); 
} 

public void onStatusChanged(String provider, int status, Bundle extras) { 
    output.append("\n\nProvider Status Changed: " + provider + ", Status=" 
      + S[status] + ", Extras=" + extras); 
} 

private void printProvider(String provider) { 
    LocationProvider info = locationManager.getProvider(provider); 
    output.append(info.toString() + "\n\n"); 
} 

private void printLocation(Location location) { 
    if (location == null) 
     output.append("\nLocation[unknown]\n\n"); 
    else 
     output.append("\n\n" + location.toString()); 
} 

} 

// main.xml 
<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" android:layout_width="fill_parent" 
android:layout_height="fill_parent"> 

    <ScrollView android:layout_width="wrap_content" 
    android:layout_height="wrap_content"> 
    <TextView android:id="@+id/output" android:layout_width="fill_parent" 
    android:layout_height="wrap_content" /> 
    </ScrollView> 
</LinearLayout>