Question

大家好我有问题，我正在进行多个asyc任务，我想在那些任务完成时调用Method。请检查。

         for (ClientsDetailDAO clientsDetailDAO : clients) {
                Log.d(TAG, "onConnected for");
                Addresses addresses = clientsDetailDAO.getAddress();
                StringBuilder sb = null;
                if (addresses != null) {
                    Log.d(TAG, "onConnected address not null");
                    sb = new StringBuilder(addresses.getStreetAddress())
                            .append(", ").append(addresses.getCity())
                            .append(", ").append(addresses.getState())
                            .append(", ").append(addresses.getZip());
                    Log.d(TAG, "Address formatted: " + sb.toString());

                    mAddressAsyncTask = new GetAddressAsyncTask(
                            clientsDetailDAO);
                    mAddressAsyncTask.execute(sb.toString());

                }
              }

私有类GetAddressAsyncTask扩展AsyncTask { private ClientsDetailDAO clientsDetailDAO;

    public GetAddressAsyncTask(ClientsDetailDAO clientsDetailDAO) {
        this.clientsDetailDAO = clientsDetailDAO;

    }

    @Override
    protected LatLng doInBackground(String... params) {
        Geocoder geoCoder = new Geocoder(getActivity());
        LatLng latLng = null;
        try {
            List<Address> addresses = geoCoder.getFromLocationName(parmas.toString,
                    1);
            Log.i(TAG, "param " + params[0] + " addresses size: "
                    + addresses.size());
            if (addresses.size() > 0) {
                latLng = new LatLng(addresses.get(0).getLatitude(),
                        addresses.get(0).getLongitude());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (isCancelled())
            return null;
        return latLng;
    }

    @Override
    protected void onPostExecute(LatLng result) {

        if (result != null) {
            Log.d(TAG, "onConnected latLng not null");
            clientsDetailDAO.setLatitude(result.latitude);
            clientsDetailDAO.setLongitude(result.longitude);

            Toast.makeText(getActivity(), "in post" + result.latitude,
                    Toast.LENGTH_LONG).show();

        } else {
            Log.d(TAG, "onConnected latLng null");
        }



    }
}

在finsih这些任务后我想调用setUpMarker（）;方法。

Answer 1

调用setUpMarker() int最新的asynctask＆＃39; onPost方法

当您有3个异步时的示例：

第一次异步运行
在第一个异步onPost
在第二个异步onPost

我们需要在onPost中调用它，以确保在调用其他asyncTask之前完成第一个asyncTask，以避免竞争条件。

Answer 2

您可以将所有任务存储在一个数组中，并在onPostExecute中检查这些任务是否已完成（使用getStatus方法）。

Answer 3

如果有固定数量的asyncs，请说2，采用全局int [2]数组。

onPostExecute{        // Async 1
  array[0]=1;
  if(checkIfAllArraySet())   
     finalMethod();
}

onPostExecute{        // Async 2
  array[1]=1;
  if(checkIfAllArraySet())   
     finalMethod();
}


boolean checkIfAllArraySet()
{
    // check if all arra[] items are 1 with a loop
}

Answer 4

启动AsyncTask（Parent），启动多个AsyncTasks（Child）。每个孩子在完成时通知父母。

    public class ParentAsyncTask extends AsyncTask... implements OnTaskCompletedListener{

    private int tasksRunning = 0;

    @Override
    protected LatLng doInBackground(...) {
        tasksRunning = clients.size();
        // spawn multiple AsyncTask
        for (ClientsDetailDAO clientsDetailDAO : clients) {
                Log.d(TAG, "onConnected for");
                Addresses addresses = clientsDetailDAO.getAddress();
                StringBuilder sb = null;
                if (addresses != null) {
                    Log.d(TAG, "onConnected address not null");
                    sb = new StringBuilder(addresses.getStreetAddress())
                            .append(", ").append(addresses.getCity())
                            .append(", ").append(addresses.getState())
                            .append(", ").append(addresses.getZip());
                    Log.d(TAG, "Address formatted: " + sb.toString());

                    mAddressAsyncTask = new GetAddressAsyncTask(
                            clientsDetailDAO);
                    mAddressAsyncTask.execute(sb.toString());

                }
        }
    }                     

    @Override
    void onTaskCompleted(...){
        tasksRunning--;
        if (tasksRunning == 0){
            doSomethingAfterAllTasksFinished();
        }           
    }

}

完成多个AsyncTask后调用Method

4 个答案: