Question

首先，抱歉我的英语不好，我是葡萄牙语，我肯定会犯一些英语语法错误。

好吧，我正在尝试使用AsyncTask类从googleMap加载地图，但是它显示了以下错误消息：

06-25 18:47:03.062: E/AndroidRuntime(8021): FATAL EXCEPTION: AsyncTask #1
06-25 18:47:03.062: E/AndroidRuntime(8021): java.lang.RuntimeException: An error occured while executing doInBackground()
06-25 18:47:03.062: E/AndroidRuntime(8021):     at java.lang.Thread.run(Thread.java:856)
06-25 18:47:03.062: E/AndroidRuntime(8021): Caused by: java.lang.IllegalStateException: Not on the main thread

我的主类调用AsyncTask类

public class ExemploGPSSimples extends FragmentActivity {

    protected GoogleMap map;

    @Override
    protected void onCreate(Bundle arg0) {
        super.onCreate(arg0);
        setContentView(R.layout.exmeplo_gps);
    }

    @Override
    protected void onResume() {
        super.onResume();
        configuraGPS();
    }

    private void configuraGPS() {
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.fragment_gps);
        map = mapFragment.getMap();
        map.setMapType(GoogleMap.MAP_TYPE_HYBRID);  
        //LatLng local=pegaPosicaoAtual();
        Localizador localizador = new Localizador(this);
        String endereco="Av. João Pessoa, 1091, Porto Alegre, RS";
        LatLng local = localizador.getEndereco(endereco);
        SincronizaMapa sincronizaMapa = new SincronizaMapa(this,local,map);
        sincronizaMapa.execute();
        adicionaMarcador(map,local);
        map.setMyLocationEnabled(true);     
    }

    private void adicionaMarcador(GoogleMap map2, LatLng local) {
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(local).title("Luiz").snippet("Casa");
        Marker marker = map2.addMarker(markerOptions);
    }


}

最后是AsyncTask类

public class SincronizaMapa extends AsyncTask<Void, Void, Void> {

    private final Activity activity;
    private final LatLng local;
    private final GoogleMap map;
    private ProgressDialog progressDialog;

    public SincronizaMapa(Activity activity, LatLng local,
            GoogleMap map) {
                this.activity = activity;
                this.local = local;
                this.map = map;

    }

    @Override
    protected void onPreExecute() {
        progressDialog = ProgressDialog.show(activity, "Sincronizando mapa", "Aguarde...",true,true);
    }

    @Override
    protected Void doInBackground(Void... params) {
        CameraPosition position = new CameraPosition.Builder()
        .target(local)
        .bearing(0)
        .tilt(0)
        .zoom(17)
        .build();
        CameraUpdate update = CameraUpdateFactory.newCameraPosition(position);
        map.animateCamera(update);
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        progressDialog.dismiss();
    }

}

谢谢大家的帮助。

Answer 1

map.animate修改UI组件（地图），因此必须在UI线程上完成。您可以将需要在UI线程上的代码移动到onPostExecute

Answer 2

问题是您正在尝试从UI线程以外的线程更新UI。 asyncTasks允许你在保持UI线程空闲的同时进行后台工作（doInBackgroud），然后根据（onPostExecute）更新UI。

你应该将doInBackground的主体放在onPostExecute的主体中 - 在UI线程上运行的方法。

AsyncTask - 不在主线程上

2 个答案: