Question

我会解释我的问题。

我有一个从上一个活动中检索数据的活动。当我点击我的按钮时，方法invokeSendQuestionChoose（）被执行。

此方法执行两项操作：在两个不同的资源上发送http请求。

第一个资源是/ nextquestion。我想用新恢复的信息刷新我的Checkbox和TextView。

OnCreate中：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.question_layout);

    idQuestion = (Integer) getIntent().getSerializableExtra("idQuestion");
    question = (String) getIntent().getSerializableExtra("question");
    answer = (String) getIntent().getSerializableExtra("answer");


    btn_yes = (Button) findViewById(R.id.btn_yes);
    tv_title_question.setText(question);
    cb_title = (CheckBox) findViewById(R.id.cb_title);

    ...
}

单击按钮时的方法：

public void invokeSendQuestionChoose(View view){

    invokeSendQuestionChoose();
    invokeNextQuestion();

}

方法http请求：

private void invokeNextQuestion(){

    class NextQuestionChooseAsync extends AsyncTask<String, Void, ArrayList<String>> {

        private Dialog loadingDialog;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // loadingDialog = ProgressDialog.show(QuestionActivity.this, "Please wait", "Loading...");
        }

        @Override
        protected ArrayList<String> doInBackground(String... params) {

            ...

            try {
                //Http request to communicate with our system
                HttpClient httpClient = new DefaultHttpClient();

                List<BasicNameValuePair> parameters = new LinkedList<BasicNameValuePair>();
                parameters.add(new BasicNameValuePair("idsession", String.valueOf(idSession)));


                HttpGet httpGet = new HttpGet();
                URI website = new URI("http://192.168.43.32:5001/nextquestion" + "?"+ URLEncodedUtils.format(parameters, "utf-8"));
                httpGet.setURI(website);

                String base64EncodedCredentials = Base64.encodeToString(
                        (email + ":" + password).getBytes(),
                        Base64.NO_WRAP);

                Log.d("test",base64EncodedCredentials);

                httpGet.setHeader("Authorization", "Basic " + base64EncodedCredentials);

                HttpResponse response = httpClient.execute(httpGet);

                statusCode = response.getStatusLine().getStatusCode();

                HttpEntity entity = response.getEntity();
                is = entity.getContent();

                BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
                StringBuilder sb = new StringBuilder();

                String line = null;
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                result = sb.toString();

                Log.d("result1", result);

                //Manage JSON result
                JSONObject jsonObject = new JSONObject(result);

                question = jsonObject.getString("question");
                idQuestion = jsonObject.getInt("idquestion");

                questionInformation.add(question);
                questionInformation.add(String.valueOf(idQuestion));

            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            } catch (URISyntaxException e) {
                e.printStackTrace();
            }

            return questionInformation;

        }

        @Override
        protected void onPostExecute(ArrayList<String> status) {
            //loadingDialog.dismiss();
            //findViewById(R.id.cb_fond).invalidate();
            String question = questionInformation.get(0);
            int idQuestion = Integer.valueOf(questionInformation.get(1));


            tv_title_question.setText(question);


        }
    }
    NextQuestionChooseAsync nqca = new NextQuestionChooseAsync();
    nqca.execute();
}

如何解决我的问题？

非常感谢。

Answer 1

将NextQuestionChooseAsync类放入其自己的文件中，并为要更改的视图创建私有字段，然后将它们从活动传递到构造函数中的NextQuestionChooseAsync。如果在asynctask期间销毁活动和textview，则使用WeakReference避免泄漏内存。

像这样：

NextQuestionChooseAsync class NextQuestionChooseAsync extends AsyncTask<String, Void, ArrayList<String>> {
    private WeakReference<TextView> mTvTitleReference;
    private Dialog loadingDialog;

    public NextQuestionChooseAsync(TextView tvTitleTextView) {
        super();
        mTvTitleReference = new WeakReference<>(tvTitleTextView);
    }
    @Override
    protected void onPostExecute(ArrayList<String> status) {
        //loadingDialog.dismiss();
        //findViewById(R.id.cb_fond).invalidate();
        String question = questionInformation.get(0);
        int idQuestion = Integer.valueOf(questionInformation.get(1));
        if (mTvTitleReference.get() != null) {
            mTvTitleReference.get().setText(question);
        }
    }
    // the rest of your code

并在invokeNextQuestion()

中

private void invokeNextQuestion() {
    NextQuestionChooseAsync nextquestionTask = new NextQuestionChooseAsync(tv_title_question);
    nextquestionTask.execute(/**put your paramters here if needed**/);
}

执行http请求时修改布局元素

1 个答案: