Question

我想获取当前的国家/地区名称，城市名称和地址行，但它返回“NULL”。当我发送经度和纬度请求时，它会返回正确的经度和纬度。

country name = null，city name = null，address line = null

    public class MainActivity extends Activity {

    TextView latitude, longitude, country, city, postalCodeTV, addressLineTV;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

     // check if GPS enabled
    GPSTracker gpsTracker = new GPSTracker(this);

    if (gpsTracker.canGetLocation())
    {
        String stringLatitude = String.valueOf(gpsTracker.latitude);
        latitude = (TextView)findViewById(R.id.fieldLatitude);
        latitude.setText("Latitude: "+stringLatitude);

        String stringLongitude = String.valueOf(gpsTracker.longitude);
        longitude = (TextView)findViewById(R.id.fieldLongitude);
        longitude.setText("Longitude: "+stringLongitude);

        String countryVal = gpsTracker.getCountryName(this);
        country = (TextView)findViewById(R.id.fieldCountry);
        country.setText("country: "+countryVal);
        System.out.println("pakistan  "+countryVal);

        String cityVal = gpsTracker.getLocality(this);
        city = (TextView)findViewById(R.id.fieldCity);
        city.setText("city: "+cityVal);

        String postalCode = gpsTracker.getPostalCode(this);
        postalCodeTV = (TextView)findViewById(R.id.fieldPostalCode);
        postalCodeTV.setText("postalCode: "+postalCode);

        String addressLine = gpsTracker.getAddressLine(this);
        addressLineTV = (TextView)findViewById(R.id.fieldAddressLine);
        addressLineTV.setText("addressLine: "+addressLine);

    }
    else
    {
        // can't get location
        // GPS or Network is not enabled
        // Ask user to enable GPS/network in settings
        gpsTracker.showSettingsAlert();
    }


    }



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
    }

}

Answer 1

您的设备应该可以连接到互联网。如果您没有互联网连接，这些值将为null。您可以使用此功能控制是否有互联网：

public boolean isInternetAvailable(Context context)
{
    NetworkInfo info = (NetworkInfo) ((ConnectivityManager)
    context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();

    if (info == null){
        return false;
    }
    else{
        return true;
    }
}

还要将这些权限添加到清单文件中：

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

祝你好运。

Answer 2

您需要将这些权限添加到清单

中

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

并在设备/模拟器上打开Gps

获取当前国家/地区显示null

2 个答案: