如何将数据从一个活动传递到当前可见/活动活动？ 这是一个好的共同点吗？

Question

I want to implement generic AsyncTasks factory in order not to write a lot of repeating code every time I want to run asynchronous operation.But I have a problem.

So I want to define this factory class in GlobalActivity which every Activity which wants to use that AsyncTasks factory should subclass, but i need to use result of doInBackground method in every active Activity which is inherited from the GlobalActivity. My idea is to define in that class some method updateCurrentActivity() which every subclass must override and do some manipulations with that doInBackground result (displaying it eg). But how to handle this result I don't know. Eg here is that factory onPostExecute definition:

protected void onPostExecute(HashMap<String, Object> result)
    {  
        currentActivityData = result;
                   //How to pass that result to the current Active
                   //activity which is overriding this method?
        updateCurrentActivity();
    }

Is it a good idea in common to create such factory. Or best practice is to write new AsyncTask... every time I want to use AsyncTask?

Answer 1

You could create your MyTask class extending AsyncTask and pass a handler in constructor from the activity you want to do the task like

final Handler mHandler = new Handler() { 

  public void handleMessage(Message msg) 
  { 
       //get your data here
       int something = msg.arg1; 
  } 
}; 

public void myMethodInsideActivity{
    new MyTask(this, mHandler).execute();
}

and call this from your pre, progressUpdate or post of your task like this

Message msg = new Message();
msg.arg1 = 1;
actHandler.sendMessage(msg);

This way you only have one task class and multiple instances, each one connected with it's activity via the handler