在我点击“btnSearch”按钮后在etSearch（EDitText）中写了一个地址后，它应该在地图中显示地址。但它给了我错误。可以帮助我
错误
02-07 19:34:30.251: E/AndroidRuntime(24364): FATAL EXCEPTION: main
02-07 19:34:30.251: E/AndroidRuntime(24364): java.lang.NullPointerException
02-07 19:34:30.251: E/AndroidRuntime(24364): at com.mamun.tasktest.MapActivity$GeocoderTask.onPostExecute(MapActivity.java:178)
02-07 19:34:30.251: E/AndroidRuntime(24364): at com.mamun.tasktest.MapActivity$GeocoderTask.onPostExecute(MapActivity.java:1)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.os.AsyncTask.finish(AsyncTask.java:631)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.os.AsyncTask.access$600(AsyncTask.java:177)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.os.Handler.dispatchMessage(Handler.java:99)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.os.Looper.loop(Looper.java:137)
02-07 19:34:30.251: E/AndroidRuntime(24364): at android.app.ActivityThread.main(ActivityThread.java:4960)
02-07 19:34:30.251: E/AndroidRuntime(24364): at java.lang.reflect.Method.invokeNative(Native Method)
02-07 19:34:30.251: E/AndroidRuntime(24364): at java.lang.reflect.Method.invoke(Method.java:511)
02-07 19:34:30.251: E/AndroidRuntime(24364): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
02-07 19:34:30.251: E/AndroidRuntime(24364): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
02-07 19:34:30.251: E/AndroidRuntime(24364): at dalvik.system.NativeStart.main(Native Method)
public class MapActivity extends Activity implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {
private LocationManager manager;
private TextView tvAddress;
private Button btnSearch;
private EditText etSearch;
private LocationClient locationClient;
private GoogleMap googleMap;
private MapFragment mapFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
manager = (LocationManager) getSystemService(LOCATION_SERVICE);
tvAddress = (TextView) findViewById(R.id.tvaddress);
btnSearch = (Button) findViewById(R.id.btnSearch);
etSearch= (EditText)findViewById(R.id.etSearch);
mapFragment = (MapFragment) getFragmentManager().findFragmentById(
R.id.maps);
googleMap = mapFragment.getMap();
locationClient = new LocationClient(this, this, this);
}
public void onSearch(View v) {
// Getting user input location
String location = etSearch.getText().toString();
if(location!=null && !location.equals("")){
new GeocoderTask().execute(location);
}
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
locationClient.connect();
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
locationClient.disconnect();
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
@Override
public void onConnectionFailed(ConnectionResult result) {
}
@Override
public void onConnected(Bundle connectionHint) {
Location currentLocation = locationClient.getLastLocation();
double lat = currentLocation.getLatitude();
double lng = currentLocation.getLongitude();
// txtLocation.setText(lat + ", " + lng);
Geocoder geocoder = new Geocoder(this);
try {
ArrayList<Address> address = (ArrayList<Address>) geocoder
.getFromLocation(currentLocation.getLatitude(),
currentLocation.getLongitude(), 5);
Address addr = address.get(0);
String currentAddress = (addr.getAddressLine(0) + "-"
+ addr.getAdminArea() + "-" + addr.getLocality() + "-"
+ addr.getPostalCode() + "-" + addr.getCountryCode());
MarkerOptions options = new MarkerOptions();
options.position(new LatLng(lat, lng));
options.title(currentAddress);
options.snippet("Current location");
options.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_AZURE));
if (googleMap != null) {
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(lat, lng), 14.0f));
googleMap.addMarker(options);
} else {
Toast.makeText(getApplicationContext(), "Map is null",
Toast.LENGTH_LONG).show();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void onDisconnected() {
// TODO Auto-generated method stub
}
// An AsyncTask class for accessing the GeoCoding Web Service
private class GeocoderTask extends AsyncTask<String, Void, ArrayList<Address>>{
@Override
protected ArrayList<Address> doInBackground(String... locationName) {
// Creating an instance of Geocoder class
Geocoder geocoder = new Geocoder(getBaseContext());
ArrayList<Address> addresses = null;
try {
// Getting a maximum of 3 Address that matches the input text
addresses = (ArrayList<Address>) geocoder.getFromLocationName(locationName[0], 3);
} catch (IOException e) {
e.printStackTrace();
}
return addresses;
}
@Override
protected void onPostExecute(ArrayList<Address> addresses) {
if(addresses==null || addresses.size()==0){
Toast.makeText(getBaseContext(), "No Location found", Toast.LENGTH_SHORT).show();
}
// Clears all the existing markers on the map
// googleMap.clear();
// Adding Markers on Google Map for each matching address
for(int i=0;i<addresses.size();i++){
Address address = (Address) addresses.get(i);
// Creating an instance of GeoPoint, to display in Google Map
LatLng latLng ;
latLng = new LatLng(address.getLatitude(), address.getLongitude());
String addressText = String.format("%s, %s",
address.getMaxAddressLineIndex() > 0 ? address.getAddressLine(0) : "",
address.getCountryName());
MarkerOptions markerOptions = new MarkerOptions();
// markerOptions = new MarkerOptions();
markerOptions.position( latLng);
markerOptions.title(addressText);
googleMap.addMarker(markerOptions);
// Locate the first location
if(i==0)
googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
}
}
}
}
答案 0 :(得分：1)
当地址为空时，您必须退出该函数。
@Override
protected void onPostExecute(ArrayList<Address> addresses) {
if(addresses==null || addresses.size()==0){
Toast.makeText(getBaseContext(), "No Location found", Toast.LENGTH_SHORT).show();
return;
}