我是android编程和堆栈溢出的新手。我的问题在于onclick方法的mylongitudey给出null值。我有3个活动。其中一个是其中之一。我想要谷歌地图的纬度和经度，并将这些点发送到另一个活动。这里的主要问题是，它没有给出纬度和经度值而是给出了空值。我无法找到错误。谁能帮我？谢谢你提前。
SharedPreferences points;
SharedPreferences.Editor ed;
Address returnedAddress;
double mylongitudey,mylatitudey;
String latilongi;
ImageView iv;
Button manual,proceed;
GoogleMap map;
LatLng mylat ;
String latlong;
Marker mymarker;
boolean markerclicked;
double mylatitudeyd,mylongitudeyd;
String addstringaa;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.two_buttons);
actionBar = getActionBar();
actionBar.setBackgroundDrawable(new ColorDrawable(Color.BLACK));
getActionBar().setDisplayHomeAsUpEnabled(true);
Toast.makeText(this,"Please select the destination by long click", Toast.LENGTH_LONG).show();
LatLng mylat;
final GoogleMap map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
map.setOnMarkerDragListener(this);
map.setTrafficEnabled(true);
// map.setOnMyLocationButtonClickListener(this);
SharedPreferences shared = getSharedPreferences("map", 0);
String mylats = (shared.getString("twolati", "NoValue"));
String mylong= (shared.getString("twolong", "NoValue"));
double dmylats = Double.valueOf(mylats);
double dmylong = Double.valueOf(mylong);
map.animateCamera(CameraUpdateFactory.zoomTo(15));
mylat = new LatLng(dmylats, dmylong);
try {
Toast.makeText(this, "This is"+mylats,Toast.LENGTH_LONG).show();
} catch (Exception e) {
Toast.makeText(this,"problem in mylat",0);
e.printStackTrace();
}
map.moveCamera(CameraUpdateFactory.newLatLngZoom(mylat, 13));
map.addMarker(new MarkerOptions().position(mylat).title("You are Here"));
markerclicked=false;
//onMyLocationButtonClick();
map.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener() {
@Override
public void onMapLongClick(LatLng arg0) {
// TODO Auto-generated method stub
if(markerclicked==false)
{
mymarker = map.addMarker(new MarkerOptions().position(arg0).title("Your Destination").draggable(true));
markerclicked=true;
}else{
Toast.makeText(getApplicationContext(), "Marker Aready Set..!", Toast.LENGTH_LONG).show();
}
}
});
map.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
LatLng mylatlong;
@Override
public void onMyLocationChange(Location arg0) {
// TODO Auto-generated method stub
mylongitudey = arg0.getLongitude();
mylatitudey = arg0.getLatitude();
mylatlong = new LatLng(arg0.getLatitude(), arg0.getLongitude());
//sourcepoint=String.format(" ",mylat);
// map.moveCamera(CameraUpdateFactory.newLatLngZoom(mylat,1));
map.moveCamera(CameraUpdateFactory.newLatLngZoom(mylatlong, 14));
}
});
// Toast.makeText(this, getmapid, Toast.LENGTH_LONG).show();
SharedPreferences pr= getSharedPreferences("reserve", 0);
latilongi=pr.getString("sourcepoint", "sourcepoint");
manual=(Button)findViewById(R.id.manuel);
manual.setOnClickListener(this);
proceed=(Button)findViewById(R.id.proceed);
proceed.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.actionmenu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Take appropriate action for each action item click
// Toast.makeText(MainActivity.this, item.getTitle(),
// Toast.LENGTH_LONG).show();
switch (item.getItemId()) {
case android.R.id.home:
if (getParentActivityIntent() == null) {
Log.i("tag", "You have forgotten to specify the parentActivityName in the AndroidManifest!");
onBackPressed();
} else {
NavUtils.navigateUpFromSameTask(this);
}
return true;
case R.id.action_refresh:
// refresh
Intent intent = new Intent(Drop_Off_Location.this, Main.class);
startActivityForResult(intent, 0);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
@Override
public void onClick(View v) {
try {
if (v.getId() == R.id.proceed) {
/* Toast.makeText(this, "address"+mylongitudey, 0);
Toast.makeText(this, " destination in DOL class "+addstringaa, 0).show();*/
points= getSharedPreferences("map", 0);
ed=points.edit();
String twolatitudey = String.valueOf(mylatitudey);
String twolongitudey = String.valueOf(mylongitudey);
ed.putString("twolatitudey",twolatitudey);
ed.putString("twolongitudey", twolongitudey);
ed.commit();
Toast.makeText(this, "dest longitude"+mylongitudey, Toast.LENGTH_LONG).show();
Intent intent = new Intent(Drop_Off_Location.this,Autofill.class);
startActivity(intent);
}
else if(v.getId()==R.id.manuel)
{
Intent intent = new Intent(Drop_Off_Location.this,Reserve.class);
startActivity(intent);
}
} catch (Exception e) {
Toast.makeText(this,"error in onclick"+e, Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
Logcat详细：
10-08 02:23:53.965: D/dalvikvm(3221): GC_FOR_ALLOC freed 111K, 25% free 7167K/9528K, paused 132ms, total 134ms
10-08 02:23:53.975: I/dalvikvm-heap(3221): Grow heap (frag case) to 9.411MB for 2457616-byte allocation
10-08 02:23:54.145: D/dalvikvm(3221): GC_FOR_ALLOC freed 2K, 20% free 9565K/11932K, paused 167ms, total 167ms
10-08 02:23:55.895: W/System.err(3221): java.io.IOException: Service not Available
10-08 02:23:55.895: W/System.err(3221): at android.location.Geocoder.getFromLocation(Geocoder.java:136)
10-08 02:23:55.905: W/System.err(3221): at jasperit.atlcitylimo.Autofill.onCreate(Autofill.java:189)
10-08 02:23:55.905: W/System.err(3221): at android.app.Activity.performCreate(Activity.java:5231)
10-08 02:23:55.905: W/System.err(3221): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
10-08 02:23:55.905: W/System.err(3221): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
10-08 02:23:55.905: W/System.err(3221): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
10-08 02:23:55.905: W/System.err(3221): at android.app.ActivityThread.access$800(ActivityThread.java:135)
10-08 02:23:55.905: W/System.err(3221): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
10-08 02:23:55.905: W/System.err(3221): at android.os.Handler.dispatchMessage(Handler.java:102)
10-08 02:23:55.905: W/System.err(3221): at android.os.Looper.loop(Looper.java:136)
10-08 02:23:55.905: W/System.err(3221): at android.app.ActivityThread.main(ActivityThread.java:5017)
10-08 02:23:55.905: W/System.err(3221): at java.lang.reflect.Method.invokeNative(Native Method)
10-08 02:23:55.915: W/System.err(3221): at java.lang.reflect.Method.invoke(Method.java:515)
10-08 02:23:55.915: W/System.err(3221): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
10-08 02:23:55.915: W/System.err(3221): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
10-08 02:23:55.915: W/System.err(3221): at dalvik.system.NativeStart.main(Native Method)
10-08 02:23:56.015: W/System.err(3221): java.io.IOException: Service not Available
10-08 02:23:56.015: W/System.err(3221): at android.location.Geocoder.getFromLocation(Geocoder.java:136)
10-08 02:23:56.035: W/System.err(3221): at jasperit.atlcitylimo.Autofill.onCreate(Autofill.java:227)
10-08 02:23:56.035: W/System.err(3221): at android.app.Activity.performCreate(Activity.java:5231)
10-08 02:23:56.035: W/System.err(3221): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
10-08 02:23:56.045: W/System.err(3221): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
10-08 02:23:56.045: W/System.err(3221): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
10-08 02:23:56.045: W/System.err(3221): at android.app.ActivityThread.access$800(ActivityThread.java:135)
10-08 02:23:56.045: W/System.err(3221): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
10-08 02:23:56.045: W/System.err(3221): at android.os.Handler.dispatchMessage(Handler.java:102)
10-08 02:23:56.045: W/System.err(3221): at android.os.Looper.loop(Looper.java:136)
10-08 02:23:56.085: W/System.err(3221): at android.app.ActivityThread.main(ActivityThread.java:5017)
10-08 02:23:56.085: W/System.err(3221): at java.lang.reflect.Method.invokeNative(Native Method)
10-08 02:23:56.085: W/System.err(3221): at java.lang.reflect.Method.invoke(Method.java:515)
10-08 02:23:56.085: W/System.err(3221): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
10-08 02:23:56.095: W/System.err(3221): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
10-08 02:23:56.095: W/System.err(3221): at dalvik.system.NativeStart.main(Native Method)
10-08 02:23:56.255: I/Choreographer(3221): Skipped 688 frames! The application may be doing too much work on its main thread.
10-08 02:23:57.585: I/Choreographer(3221): Skipped 267 frames! The application may be doing too much work on its main thread.
10-08 02:23:58.885: I/Choreographer(3221): Skipped 114 frames! The application may be doing too much work on its main thread.
10-08 02:23:59.675: I/Choreographer(3221): Skipped 107 frames! The application may be doing too much work on its main thread.
答案 0 :(得分：1)
//instance variables
private GoogleMap googleMap;
private double longitude = 0.0;
private double latitude = 0.0;
private LocationManager locationManager = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); // your layout
try {
initilizeMap();
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 1, this);
googleMap.setMyLocationEnabled(true);
googleMap.getUiSettings().setMyLocationButtonEnabled(true);
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void initilizeMap() {
if (googleMap == null) {
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap(); //provide your id
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
longitude = location.getLongitude();
latitude = location.getLatitude();
//System.out.println(latitude+ " "+longitude );
if(!isStopFocusEnabled){
CameraPosition cameraPosition = new CameraPosition.Builder().target(
new LatLng(latitude, longitude)).zoom(12).build();
googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
}
在Manifest下面的代码必须在那里
<permission
android:name="com.ani.map.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-permission android:name="com.ani.map.permission.MAPS_RECEIVE" />
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<!-- Required to show current location -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- Required OpenGL ES 2.0. for Maps V2 -->
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<!-- Goolge API Key -->
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="YOUR KEY" />
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version"/>
//相应地改变它......它肯定会起作用......
答案 1 :(得分：-1)
public boolean onTouchEvent(MotionEvent event)
{
int X = (int)event.getX();
int Y = (int)event.getY();
GeoPoint geoPoint = mapView.getProjection().fromPixels(X, Y);
}