如何在xml屏幕上显示'double'纬度和经度字符串

Question

我需要有关在屏幕上显示经度和纬度的帮助（geolocation.xml）。当按下 'retrive location' 按钮时，Toast 消息给出位置坐标右（经度和纬度）的值。

但是当我试图在 geolocation.xml 上显示它时 @id/tvLatitude 和 @id/tvLongitude 没有显示任何东西（只是空白）。

经度和纬度在 'double'.

这是代码的一部分：

>     protected void showCurrentLocation() {
>        
>               Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
>        
>               if (location != null) {
>                   String message = String.format(
>                           "Current Location \n Longitude: %1$s \n Latitude: %2$s",
>                           location.getLongitude(), location.getLatitude()
>                   );
>                   Toast.makeText(LbsGeocodingActivity.this, message,
>                           Toast.LENGTH_LONG).show();
>                   
>                   String tvLongitude = String.valueOf(location.getLongitude());
>                   String tvLatitude = String.valueOf(location.getLatitude());
>                   
>     
>             
>               }

我的屏幕 geolocation.xml 是：

>     android:layout_width="wrap_content"
>     
>        android:layout_height="wrap_content"
>     
>        />
>        
>        <TextView android:layout_width="fill_parent"
>             android:id="@+id/texLongitude "
>             android:layout_height="wrap_content"
>             android:text="Outlet Longitude"
>             android:paddingLeft="10dip"
>             android:paddingRight="10dip"
>             android:paddingTop="10dip"
>             android:textSize="17dip"/>
>         
>         <!-- Input Name -->
>       <TextView 
>           android:id="@+id/tvLongitude"
>           android:layout_width="fill_parent"
>           android:layout_height="wrap_content"
>           android:layout_margin="5dip"
>           android:layout_marginBottom="15dip"
>           
>           android:singleLine="true"/>
>       
>        
>        <TextView android:layout_width="fill_parent"
>             android:id="@+id/texLatitude "
>             android:layout_height="wrap_content"
>             android:text="Outlet Latitude"
>             android:paddingLeft="10dip"
>             android:paddingRight="10dip"
>             android:paddingTop="10dip"
>             android:textSize="17dip"/>
>         
>         <!-- Input Name -->
>       <TextView 
>           android:id="@+id/tvLatitude"
>           android:layout_width="fill_parent"
>           android:layout_height="wrap_content"
>           android:layout_margin="5dip"
>           android:layout_marginBottom="15dip"
>           
>           android:singleLine="true"/>
>       
>     
>       </LinearLayout>

使用 String.valueOf(location.getLongitude()) 在屏幕上显示 double to string 的方法是否正确？还有其他办法吗？

我是 android 和 java 编程的新手。非常感谢。

这是我的 Activity（已满）。 showCurrentLocation 是其中的一种方法。

> public class LbsGeocodingActivity extends Activity {
>        
>       private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 10; // in Meters
>       private static final long MINIMUM_TIME_BETWEEN_UPDATES = 60000; // in Milliseconds
>   
>        
>       protected LocationManager locationManager;
>        
>       protected Button retrieveLocationButton;
>        
>       @Override
>       public void onCreate(Bundle savedInstanceState) {
>            
>           super.onCreate(savedInstanceState);
>           setContentView(R.layout.geolocation);
>    
>           retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
>            
>           locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
>            
>           locationManager.requestLocationUpdates(
>                   LocationManager.GPS_PROVIDER, 
>                   MINIMUM_TIME_BETWEEN_UPDATES, 
>                   MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
>                   new MyLocationListener()
>           );
>            
>       retrieveLocationButton.setOnClickListener(new OnClickListener() {
>               @Override
>               public void onClick(View v) {
>                   showCurrentLocation();
>               }
>       });        
>            
>       }    
>    
>       protected void showCurrentLocation() {
>    
>           Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
>    
>           if (location != null) {
>               String message = String.format(
>                       "Current Location \n Longitude: %1$s \n Latitude: %2$s",
>                       location.getLongitude(), location.getLatitude()
>               );
>               Toast.makeText(LbsGeocodingActivity.this, message,
>                       Toast.LENGTH_LONG).show();
>               
>               
>              ((TextView)findViewById(R.id.tvLatitude)).setText(""+location.getLatitude());
>              ((TextView)findViewById(R.id.tvLongitude)).setText(""+location.getLongitude());
>         
>           }
>    
>       }   
>    
>       private class MyLocationListener implements LocationListener {
>   
>           public void onLocationChanged(Location location) {
>               String message = String.format(
>                       "New Location \n Longitude: %1$s \n Latitude: %2$s",
>                       location.getLongitude(), location.getLatitude()
>               );
>               Toast.makeText(LbsGeocodingActivity.this, message, Toast.LENGTH_LONG).show();
>           }
>    
>           public void onStatusChanged(String s, int i, Bundle b) {
>               Toast.makeText(LbsGeocodingActivity.this, "Provider status changed",
>                       Toast.LENGTH_LONG).show();
>           }
>    
>           public void onProviderDisabled(String s) {
>               Toast.makeText(LbsGeocodingActivity.this,
>                       "Provider disabled by the user. GPS turned off",
>                       Toast.LENGTH_LONG).show();
>           }
>    
>           public void onProviderEnabled(String s) {
>               Toast.makeText(LbsGeocodingActivity.this,
>                       "Provider enabled by the user. GPS turned on",
>                       Toast.LENGTH_LONG).show();
>           }
>    
>       }
>           }

Answer 1

改为

> public class LbsGeocodingActivity extends Activity {
>        
>       private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 10; // in Meters
>       private static final long MINIMUM_TIME_BETWEEN_UPDATES = 60000; // in Milliseconds
>   
>        
>       protected LocationManager locationManager;
>        
>       protected Button retrieveLocationButton;
>       private TextView tv1,tv2;

> 
>       @Override
>       public void onCreate(Bundle savedInstanceState) {
>            
>           super.onCreate(savedInstanceState);
>           setContentView(R.layout.geolocation);
>    
>           retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);

           tv1 = (TextView)findViewById(R.id.tvLatitude);
           tv2 = (TextView)findViewById(R.id.tvLongitude);

>           locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
>            
>           locationManager.requestLocationUpdates(
>                   LocationManager.GPS_PROVIDER, 
>                   MINIMUM_TIME_BETWEEN_UPDATES, 
>                   MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
>                   new MyLocationListener()
>           );
>            
>       retrieveLocationButton.setOnClickListener(new OnClickListener() {
>               @Override
>               public void onClick(View v) {
>                   showCurrentLocation();
>               }
>       });        
>            
>       }    
>    
>       protected void showCurrentLocation() {
>    
>           Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
>    
>           if (location != null) {
>               String message = String.format(
>                       "Current Location \n Longitude: %1$s \n Latitude: %2$s",
>                       location.getLongitude(), location.getLatitude()
>               );
>               Toast.makeText(LbsGeocodingActivity.this, message,
>                       Toast.LENGTH_LONG).show();
>               
>               
>              tv1.setText(""+location.getLatitude());
>              tv2.setText(""+location.getLongitude());
>         
>           }
>    
>       }

如何在xml屏幕上显示'double'纬度和经度字符串

How to display 'double' latitude and longitude to string on the xml screen

android

xml

string

double

screen