当我在设备上关闭 GPS 的情况下加载此活动时，它会使应用程序崩溃。
我将如何解决这个问题？
如果可能的话，如果关闭 GPS 以改用 COARSE_LOCATION 也会很神奇，但不确定这会多么容易。
任何帮助将不胜感激，代码如下：
public class SunriseSunset extends Activity implements OnClickListener {
public Button getLocation;
public Button setLocationJapan;
public TextView LongCoord;
public TextView LatCoord;
public double longitude;
public double latitude;
public LocationManager lm;
public Spinner Locationspinner;
public DateDialogFragment frag;
public Button date;
public Calendar now;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sunrisesunset);
// Show the Up button in the action bar.
setupActionBar();
//Setting onClickListener for Calculate Sunrise/Sunset Button
findViewById(R.id.CalculateSunriseSunset).setOnClickListener(this);
//Sets up LocationManager to enable GPS data to be accessed.
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 1,
new MyLocationListener());
//Declares Latitude and Longitude TextViews
LatCoord = (TextView) findViewById(R.id.LatCoord);
LongCoord = (TextView) findViewById(R.id.LongCoord);
//Declares for Location Spinner/Dropdown
addListenerOnSpinnerItemSelection();
//Date shit
now = Calendar.getInstance();
date = (Button)findViewById(R.id.date_button);
date.setText(DateFormat.format("dd MMMM yyyy", Calendar.getInstance()));
date.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showDialog();
}
});
}
/**
* Set up the {@link android.app.ActionBar}.
*/
private void setupActionBar() {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
// More date shit
@SuppressLint("CommitTransaction")
public void showDialog() {
FragmentTransaction ft = getFragmentManager().beginTransaction(); //get the fragment
frag = DateDialogFragment.newInstance(this, new DateDialogFragmentListener(){
public void updateChangedDate(int year, int month, int day){
now.set(year, month, day);
date.setText(DateFormat.format("dd MMMM yyyy", now));
}
}, now);
frag.show(ft, "DateDialogFragment"); }
public interface DateDialogFragmentListener{
//this interface is a listener between the Date Dialog fragment and the activity to update the buttons date
public void updateChangedDate(int year, int month, int day);
}
public void addListenerOnSpinnerItemSelection() {
Locationspinner = (Spinner) findViewById(R.id.Locationspinner);
Locationspinner
.setOnItemSelectedListener(new LocationOnItemSelectedListener(
this));
}
//Sets locations for all the cities in the spinner
public void setLocationAuckland() {LatCoord.setText("-36.85248273");LongCoord.setText("174.76391734");}
public void setLocationBuenoAires() {LatCoord.setText("-34.606358325");LongCoord.setText("-58.38727463");}
public void setLocationCalgary()
protected void showCurrentLocation() {
// TODO Auto-generated method stub
// This is called to find current location based on GPS data and sends
// these values to the LongCoord and LatCoord TextViews
Location location = lm
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
latitude = location.getLatitude();
longitude = location.getLongitude();
LongCoord.setText(Double.toString(longitude));
LatCoord.setText(Double.toString(latitude));
}
@Override
public void onClick(View arg0) {
Button b = (Button) findViewById(R.id.CalculateSunriseSunset);
b.setClickable(false);
new LongRunningGetIO().execute();
}
public class LongRunningGetIO extends AsyncTask<Void, Void, String> {
//Reads in the web service
protected String getASCIIContentFromEntity(HttpEntity entity)
throws IllegalStateException, IOException {
InputStream in = entity.getContent();
StringBuffer out = new StringBuffer();
int n = 1;
while (n > 0) {
byte[] b = new byte[4096];
n = in.read(b);
if (n > 0)
out.append(new String(b, 0, n));
}
return out.toString();
}
private final ProgressDialog dialog = new ProgressDialog(SunriseSunset.this);
protected void onPreExecute() {
this.dialog.setMessage("Calculating...");
this.dialog.show();
}
@SuppressLint("SimpleDateFormat")
@Override
protected String doInBackground(Void... params) {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
// Finds todays date and adds that into the URL in simple date format DD/MM
SimpleDateFormat df = new SimpleDateFormat("dd/MM");
String formattedDate = df.format(now.getTime());
String finalURL = "http://www.earthtools.org/sun/"
+ LatCoord.getText().toString().trim() + "/"
+ LongCoord.getText().toString().trim() + "/"
+ formattedDate + "/99/0";
HttpGet httpGet = new HttpGet(finalURL);
String text = null;
try {
HttpResponse response = httpClient.execute(httpGet,
localContext);
HttpEntity entity = response.getEntity();
text = getASCIIContentFromEntity(entity);
} catch (Exception e) {
return e.getLocalizedMessage();
}
return text;
}
protected void onPostExecute(String results) {
//Closes dialog box onPostExecute
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
//Finds TextViews for Sunrise and Sunset values and posts results
if (results != null) {
try {
DocumentBuilderFactory dbFactory = DocumentBuilderFactory
.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
InputSource s = new InputSource(new StringReader(results));
Document doc = dBuilder.parse(s);
doc.getDocumentElement().normalize();
TextView tvSunrise = (TextView) findViewById(R.id.Sunrise);
TextView tvSunset = (TextView) findViewById(R.id.Sunset);
tvSunrise.setText(doc.getElementsByTagName("sunrise").item(0).getTextContent());
tvSunset.setText(doc.getElementsByTagName("sunset").item(0).getTextContent());
} catch (Exception e) {
e.printStackTrace();
}
}
Button b = (Button) findViewById(R.id.CalculateSunriseSunset);
b.setClickable(true);
}
}
class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.home, menu);
return true;
}
public boolean onPrepareOptionsMenu(Menu menu) {
// preparation code here
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
if (item.getItemId() == R.id.LessonsTutorials) {
startActivity(new Intent(this, Lessons.class));
}
if (item.getItemId() == R.id.PhotoTools) {
startActivity(new Intent(this, Tools.class));
}
if (item.getItemId() == R.id.Glossary) {
startActivity(new Intent(this, Glossary.class));
}
if (item.getItemId() == R.id.Help) {
startActivity(new Intent(this, Help.class));
}
return super.onOptionsItemSelected(item);
}
}
感谢您的关注
编辑：
根据要求输出 LogCat：
04-19 11:45:06.211: I/Adreno200-EGL(29691): Build Date: 12/10/12 Mon
04-19 11:45:06.211: I/Adreno200-EGL(29691): Local Branch:
04-19 11:45:06.211: I/Adreno200-EGL(29691): Remote Branch: m/partner-android/jb-mr1-dev
04-19 11:45:06.211: I/Adreno200-EGL(29691): Local Patches: NONE
04-19 11:45:06.211: I/Adreno200-EGL(29691): Reconstruct Branch: NOTHING
04-19 11:45:06.241: D/OpenGLRenderer(29691): Enabling debug mode 0
04-19 11:45:10.215: D/AndroidRuntime(29691): Shutting down VM
04-19 11:45:10.215: W/dalvikvm(29691): threadid=1: thread exiting with uncaught exception (group=0x414a1930)
04-19 11:45:10.225: E/AndroidRuntime(29691): FATAL EXCEPTION: main
04-19 11:45:10.225: E/AndroidRuntime(29691): java.lang.NullPointerException
04-19 11:45:10.225: E/AndroidRuntime(29691): at richgrundy.learnphotography.SunriseSunset.showCurrentLocation(SunriseSunset.java:148)
04-19 11:45:10.225: E/AndroidRuntime(29691): at richgrundy.learnphotography.LocationOnItemSelectedListener.onItemSelected(LocationOnItemSelectedListener.java:20)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.widget.AdapterView.fireOnSelected(AdapterView.java:892)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.widget.AdapterView.access$200(AdapterView.java:49)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:860)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.os.Handler.handleCallback(Handler.java:725)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.os.Handler.dispatchMessage(Handler.java:92)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.os.Looper.loop(Looper.java:137)
04-19 11:45:10.225: E/AndroidRuntime(29691): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-19 11:45:10.225: E/AndroidRuntime(29691): at java.lang.reflect.Method.invokeNative(Native Method)
04-19 11:45:10.225: E/AndroidRuntime(29691): at java.lang.reflect.Method.invoke(Method.java:511)
04-19 11:45:10.225: E/AndroidRuntime(29691): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-19 11:45:10.225: E/AndroidRuntime(29691): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-19 11:45:10.225: E/AndroidRuntime(29691): at dalvik.system.NativeStart.main(Native Method)
编辑：
是不是因为我在这里调用 GPS_PROVIDER：
protected void showCurrentLocation() {
// TODO Auto-generated method stub
// This is called to find current location based on GPS data and sends
// these values to the LongCoord and LatCoord TextViews
Location location = lm
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
latitude = location.getLatitude();
longitude = location.getLongitude();
LongCoord.setText(Double.toString(longitude));
LatCoord.setText(Double.toString(latitude));
}