并行执行多个AsyncTask

Question

我正在使用Android SDK 4.0.3 API15,我希望并行运行多个AsyncTasks.我从Web服务器获取数据并实时动画(10 fps).但是根据用户操作,我还需要将一些数据发送到Web服务器.当发生这种情况时,我的动画暂停一小段时间(发送数据进入队列并获取数据等待它完成)因此我无法捕捉实时.

这个答案很有说服力,但我无法使其发挥作用.所以任何帮助都将非常感激.

我想我需要使用这个功能来实现:

AsyncTask.executeOnExecutor(Executor exec, Params... params)

但我无法将执行程序作为参数传递,我无法实例化执行程序.这是我的AsyncTask类:

public class GetPlayers extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {

        Thread.currentThread().setPriority(Thread.MAX_PRIORITY);

        rawData="";
        for (String url : urls) {
            DefaultHttpClient client = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(url);
            try {
                HttpResponse execute = client.execute(httpGet);
                InputStream content = execute.getEntity().getContent();

                BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                if((rawData = buffer.readLine()) == null){
                    rawData = "error";
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return rawData; 
    }

    @Override
    protected void onPostExecute(String result) {
        manipulate();
    }
}

我执行它是这样的:

GetPlayers task = new GetPlayers();
requestString = "web adress is here...";
task.execute(new String[] { requestString });

Answer 1

这就是我这样做的方式:

if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) {
    new MyAsyncTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
} else {
    new MyAsyncTask().execute();
}

其中MyAsyncTask是常规的AsyncTask子类.或者你可以将这一切包装在helper类中:

class TaskHelper {

    public static <P, T extends AsyncTask<P, ?, ?>> void execute(T task) {
        execute(task, (P[]) null);
    }

    @SuppressLint("NewApi")
    public static <P, T extends AsyncTask<P, ?, ?>> void execute(T task, P... params) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, params);
        } else {
            task.execute(params);
        }
    }
}

然后就是:

TaskHelper.execute( new MyTask() );

要么

TaskHelper.execute( new MyTask(), args );

要么

TaskHelper.execute( new MyTask(constructorParams), args );