Question

我正在尝试为我的JsonArray创建一个异步任务，因为它正在跳帧和滞后。我创建了一个放入参数的asyncTask类，我在后台执行了调用我的Json请求，但是，我现在如何在我的postexecute方法中引用我的Json onresponse？

class MyTask extends AsyncTask<URL,String,JSONArray> {
        @Override
        protected JSONArray doInBackground(URL... params) {
            JsonRequestMethod();

            return null;
        }

        @Override
        protected void onPostExecute(JSONArray response) {

        }
    }
}


private void JsonRequestMethod() {
            mVolleySingleton = VolleySingleton.getInstance();
            //intitalize Volley Singleton request key
            mRequestQueue = mVolleySingleton.getRequestQueue();
            //2 types of requests an Array request and an Object Request
            JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET, URL_API, (String) null, new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    listblogs.clear();
                    listblogs=parseJSONResponse(response);
                    mAdapterDashBoard.setBloglist(listblogs);


                    System.out.println("it worked!!!");
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                }
            });
            mRequestQueue.add(request);
    }
private ArrayList<Blogs> parseJSONResponse(JSONArray response) {
    if (!response.equals("")) {
        ArrayList<Blogs> blogsArrayList = new ArrayList<>();
        try {
            StringBuilder data = new StringBuilder();
            for (int i = 0; i < response.length(); i++) {
                JSONObject currentQuestions = response.getJSONObject(i);
                String text = currentQuestions.getString("text");
                String points = currentQuestions.getString("points");
                String ID=currentQuestions.getString("id");
                String studentId = currentQuestions.getString("studentId");
                String DateCreated=currentQuestions.getString("created");
                long time=Long.parseLong(DateCreated.trim());
                data.append(text + "\n" + points + "\n");
                System.out.println(data);
                Blogs blogs = new Blogs();
                blogs.setId(ID);
                blogs.setMstudentId(studentId);
                blogs.setMtext(text);
                blogs.setPoints(points);
                //The dateCreated was off by 1 hour so 3600000 ms where added=1hour, (UPDATE)
                blogs.setDateCreated(getTimeAgo(time));
                System.out.println(time+"time");


                listblogs.add(blogs);

            }

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
    return listblogs;
}

Answer 1

你的截击请求已经异步，这就是为什么它有onResponse()和onErrorResponse()等侦听器接口。你根本不需要它AsyncTask。从UI线程调用您的截击请求，并使用AsyncTask来解析JSON。例如：

拨打你的截击请求。
在您的截击请求的onResponse()中，创建AsyncTask以处理解析。
在doInBackground()方法中解析JSON，“返回”解析的结果。
您的onPostExecute()会收到解析“结果”，您可以在那里做你想做的事。

为了更进一步，您可以为您的AsyncTask实现一个侦听器接口，例如onJSONParsed()，然后您可以在UI线程中设置逻辑（您调用您的截击请求），以处理100 ％完成回复。例如：

class MyTask extends AsyncTask<URL,String,ArrayList<Blogs>> {
    // Listener member variable.
    private OnJSONParsedListener mOnJSONParsedListener;

    @Override
    protected ArrayList<Blog> doInBackground(URL... params) {
        // Parse JSON.
        ArrayList<Blogs> blogsList = parseJSON(response);

        // Pass the blogs list to the onPostExecute method.
        return blogsList;
    }

    @Override
    protected void onPostExecute(ArrayList<Blogs> blogsList) {
        // Invoke listener, if present.
        if (mOnJSONParsedListener != null)
            mOnJSONParsedListener.onJSONParsed(blogsList);
    }

    // Listener interface.
    public interface OnJSONParsedListener {
        void onJSONParsed(ArrayList<Blogs> blogsList);
    }

    // Setter for listener interface member variable.
    public void setOnJSONParsedListener(OnJSONParsedListener listener) {
        mOnJSONParsedListener = listener;
    }
}

然后在你的UI线程中。

// Call your volley request.
mVolleySingleton = VolleySingleton.getInstance();

//intitalize Volley Singleton request key
mRequestQueue = mVolleySingleton.getRequestQueue();

//2 types of requests an Array request and an Object Request
JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET, URL_API, (String) null, new Response.Listener<JSONArray>() {
    @Override
    public void onResponse(JSONArray response) {
        // Create AsyncTask.
        MyTask parseJSONTask = new MyTask();

        // Set listener interface.
        parseJSONTask.setOnJSONParsedListener(new MyTask.OnJSONParsedListener() {
            @Override
            public void onJSONParsed(ArrayList<Blogs> blogsList) {
                // Do stuff with your blogs list.
                mAdapterDashBoard.setBloglist(blogsList);

                // It worked!
                System.out.println("it worked!!!");
            }
        }

        // Execute.
        parseJSONTask.execute(response);
    }
}, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
    }
});
mRequestQueue.add(request);

希望这有帮助。

如何在我的postexecute方法中引用我的JSON onResponse？

1 个答案: