android-如何在AsyncTask中执行功能？

概述我必须在AsyncTask中使用directions()函数来避免在UI线程上进行网络处理.我无法执行此 *** 作.我的代码是publicclassMainActivityextendsMapActivity{@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceSt

我必须在AsyncTask中使用directions()函数来避免在UI线程上进行网络处理.我无法执行此 *** 作.
我的代码是

    public class MainActivity extends MapActivity {    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_main);        MapVIEw mapVIEw = (MapVIEw) findVIEwByID(R.ID.mapvIEw); //or you can declare it directly with the API key        Route route = directions(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));        RouteOverlay routeOverlay = new RouteOverlay(route, color.BLUE);        mapVIEw.getoverlays().add(routeOverlay);        mapVIEw.invalIDate();    }    private Route directions(final GeoPoint start, final GeoPoint dest) {        Parser parser;        //https://developers.Google.com/maps/documentation/directions/#JsON <- get API        String JsonURL = "http://maps.GoogleAPIs.com/maps/API/directions/Json?";        final StringBuffer sBuf = new StringBuffer(JsonURL);        sBuf.append("origin=");        sBuf.append(start.getLatitudeE6()/1E6);        sBuf.append(',');        sBuf.append(start.getLongitudeE6()/1E6);        sBuf.append("&destination=");        sBuf.append(dest.getLatitudeE6()/1E6);        sBuf.append(',');        sBuf.append(dest.getLongitudeE6()/1E6);        sBuf.append("&sensor=true&mode=driving");        parser = new GoogleParser(sBuf.toString());        Route r =  parser.parse();        return r;    }    @OverrIDe    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }    @OverrIDe    protected boolean isRoutedisplayed() {        // Todo auto-generated method stub        return false;    }}

解决方法:

也许是这样吗？

public class MainActivity extends MapActivity {    private MapVIEw mapVIEw;    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_main);        mapVIEw = (MapVIEw) findVIEwByID(R.ID.mapvIEw); //or you can declare it directly with the API key        // You can execute it at onCreate or whenever you want, for example: in a click event        new AsyncRoutes().execute();    }    private Route directions(final GeoPoint start, final GeoPoint dest) {        Parser parser;        //https://developers.Google.com/maps/documentation/directions/#JsON <- get API        String JsonURL = "http://maps.GoogleAPIs.com/maps/API/directions/Json?";        final StringBuffer sBuf = new StringBuffer(JsonURL);        sBuf.append("origin=");        sBuf.append(start.getLatitudeE6()/1E6);        sBuf.append(',');        sBuf.append(start.getLongitudeE6()/1E6);        sBuf.append("&destination=");        sBuf.append(dest.getLatitudeE6()/1E6);        sBuf.append(',');        sBuf.append(dest.getLongitudeE6()/1E6);        sBuf.append("&sensor=true&mode=driving");        parser = new GoogleParser(sBuf.toString());        Route r =  parser.parse();        return r;    }    @OverrIDe    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }    @OverrIDe    protected boolean isRoutedisplayed() {        // Todo auto-generated method stub        return false;    }    private class AsyncRoutes extends AsyncTask<VoID, Integer, Route> {        private ProgressDialog pDialog;        @OverrIDe        protected voID onPreExecute() {            pDialog = new ProgressDialog(LoginActivity.this);            pDialog.setProgressstyle(ProgressDialog.STYLE_SPINNER);            pDialog.setMessage("Obtaining routes...");            pDialog.setCancelable(false);            pDialog.show();        }        @OverrIDe        protected Route doInBackground(VoID... params) {            Route route = directions(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));            return route;        }        @OverrIDe        protected voID onPostExecute(Route route) {                     RouteOverlay routeOverlay = new RouteOverlay(route, color.BLUE);            mapVIEw.getoverlays().add(routeOverlay);            mapVIEw.invalIDate();            pDialog.dismiss();        }    }}

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