我有一个使用谷歌地图视图的应用程序。该代码在我的旧设备 android 2.1 上运行良好，但在我的 htc one x 运行 android 4 上，我不得不对其进行异步以避免主线程上的网络异常。
地图视图显示敌人大约一秒钟，然后它就崩溃了。该错误包含一个异常，该异常引用了未调用 Looper.prepare() 的线程。任何想法我如何解决它谢谢。
这是例外，我将在下面发布源代码。
11-14 13:29:31.025: W/dalvikvm(20404): threadid=15: thread exiting with uncaught exception (group=0x40a7d228)
11-14 13:29:31.025: E/AndroidRuntime(20404): FATAL EXCEPTION: AsyncTask #4
11-14 13:29:31.025: E/AndroidRuntime(20404): java.lang.RuntimeException: An error occured while executing doInBackground()
11-14 13:29:31.025: E/AndroidRuntime(20404): at android.os.AsyncTask$3.done(AsyncTask.java:278)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.lang.Thread.run(Thread.java:864)
11-14 13:29:31.025: E/AndroidRuntime(20404): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
11-14 13:29:31.025: E/AndroidRuntime(20404): at android.os.Handler.<init>(Handler.java:121)
11-14 13:29:31.025: E/AndroidRuntime(20404): at android.widget.ZoomButtonsController$2.<init>(ZoomButtonsController.java:170)
11-14 13:29:31.025: E/AndroidRuntime(20404): at android.widget.ZoomButtonsController.<init>(ZoomButtonsController.java:170)
11-14 13:29:31.025: E/AndroidRuntime(20404): at com.google.android.maps.MapView.createZoomButtonsController(MapView.java:1444)
11-14 13:29:31.025: E/AndroidRuntime(20404): at com.google.android.maps.MapView.setBuiltInZoomControls(MapView.java:1498)
11-14 13:29:31.025: E/AndroidRuntime(20404): at com.carefreegroup.GetClientDirections.getRoute(GetClientDirections.java:173)
11-14 13:29:31.025: E/AndroidRuntime(20404): at com.carefreegroup.GetClientDirections$AsyncGetRoute.doInBackground(GetClientDirections.java:87)
11-14 13:29:31.025: E/AndroidRuntime(20404): at com.carefreegroup.GetClientDirections$AsyncGetRoute.doInBackground(GetClientDirections.java:1)
11-14 13:29:31.025: E/AndroidRuntime(20404): at android.os.AsyncTask$2.call(AsyncTask.java:264)
11-14 13:29:31.025: E/AndroidRuntime(20404): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
.
public class GetClientDirections extends MapActivity {
private MapController mapController;
private MapView mapView;
private List<Overlay> mapOverlays;
private StringBuffer response = null;
private static final String TAG = GetClientDirections.class.getSimpleName();
private double lon;
private double lat;
private JSONArray routes = null;
private JSONObject bounds = null;
private JSONObject northeast = null;
private JSONObject anonObject;
private JSONObject overViewPolyline;
private String stringUrl;
private String polyPoints;
Context context;
private String endAddr;
private String startAddr;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mapview);
context = this;
startAddr = "wf120lj";
endAddr = "wf27ar";
StringBuilder sb = new StringBuilder();
sb.append("http://maps.google.com/maps/api/directions/json?origin=");
sb.append(startAddr);
sb.append("&destination=");
sb.append(endAddr);
sb.append("&sensor=false");
stringUrl = sb.toString();
Log.e(TAG, "url = " + stringUrl);
AsyncGetRoute agr = new AsyncGetRoute();
agr.execute();
}// end of onCreate
private class AsyncGetRoute extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
getRoute();
return null;
}
}
public void getRoute() {
response = new StringBuffer();
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
HttpURLConnection httpconn = null;
try {
httpconn = (HttpURLConnection) url.openConnection();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
if (httpconn.getResponseCode() == HttpURLConnection.HTTP_OK) {
// Log.e(TAG,"response code OK ");
BufferedReader input = new BufferedReader(
new InputStreamReader(httpconn.getInputStream()), 8192);
String strLine = null;
while ((strLine = input.readLine()) != null) {
// Log.e(TAG,""+strLine);
response.append(strLine);
}
input.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String jsonOutput = response.toString();
Log.e(TAG, "jsonOutput = " + jsonOutput);
JSONObject results = null;
try {
results = new JSONObject(jsonOutput);
routes = results.getJSONArray("routes");
anonObject = routes.getJSONObject(0);
bounds = anonObject.getJSONObject("bounds");
overViewPolyline = anonObject.getJSONObject("overview_polyline");
polyPoints = overViewPolyline.getString("points");
Log.e(TAG, "overview_polyline = " + overViewPolyline);
Log.e(TAG, "points = " + polyPoints);
northeast = bounds.getJSONObject("northeast");
lat = (Double) northeast.get("lat");
lon = (Double) northeast.get("lng");
Log.e(TAG, "lon/lat = " + lon + " " + lat);
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
List<GeoPoint> list = decodePoly(polyPoints);
mapView = (MapView) findViewById(R.id.cfmapview);
mapView.setBuiltInZoomControls(true);
mapView.setEnabled(true);
mapView.setSatellite(true);
mapController = mapView.getController();
mapController.setZoom(10);
mapOverlays = mapView.getOverlays();
mapOverlays.add(new RoutePathOverlay(list, getApplicationContext()));
mapController.animateTo(new GeoPoint(list.get(0).getLatitudeE6(), list
.get(0).getLongitudeE6()));
mapView.invalidate();
}// end of getRoute
private List<GeoPoint> decodePoly(String encoded) {
List<GeoPoint> poly = new ArrayList<GeoPoint>();
int index = 0, len = encoded.length();
int lat = 0, lng = 0;
while (index < len) {
int b, shift = 0, result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
GeoPoint p = new GeoPoint((int) (((double) lat / 1E5) * 1E6),
(int) (((double) lng / 1E5) * 1E6));
poly.add(p);
}
return poly;
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
}