如何从 onPostExecute 方法存储值

Question

我在活动旁边有一个片段。我想创建一个单独扩展 AsyncTask 的类。我如何从片段中执行 AsyncTask 并在片段中获取 Asyntask 类的值。 例如假设它是我的片段类

public class FeePayFragment extends android.support.v4.app.Fragment{
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootview = inflater.inflate(R.layout.fragment_fee_pay, container, false);}
}

这里是异步任务

public class AsyFeeDues extends AsyncTask<Void,Void,Void> {
        JSONArray rootJsonArray;
        JSONObject rootJsonObject;
        private String compCode,session,admNo;
        boolean checkSeverResponse;
        public AsyFeeDues(String compCode, String session, String admNo) {
            this.compCode = compCode;
            this.session = session;
            this.admNo = admNo;
        }
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            progressDialog = new ProgressDialog(getActivity());
            progressDialog.setMessage("Please Wait....");
            progressDialog.show();
        }
        @Override
        protected Void doInBackground(Void... params) {


            RestApi api = new RestApi();
            try {
                rootJsonObject = api.GetFeeDues(compCode, session, admNo);
                checkSeverResponse  = (rootJsonObject != null);
                if(checkSeverResponse) {
                    boolean isSuccess = rootJsonObject.optBoolean(TAG_SUCESSFULL);
                    rootJsonArray = rootJsonObject.optJSONArray(TAG_VALUE);

                    for (int i = 0; i < rootJsonArray.length(); i++) {

                        JSONObject jsonObject = rootJsonArray.optJSONObject(i);
                        int amount = jsonObject.optInt(TAG_AMOUNT);
                        if (amount > 0) {
                            int period = jsonObject.optInt(TAG_PERIOD);
                            if (period <= periodMonth) {
                                String feeCode = jsonObject.optString(TAG_FEECODE);
                                String feeHead = jsonObject.optString(TAG_FEEHEAD);
                                String periodName = jsonObject.optString(TAG_PERIODNAME);

                                boolean checkFeeKey = feeDuesDetails.containsKey(feeHead);
                                if (checkFeeKey) {
                                    totalBalanceAmount = totalBalanceAmount + amount;
                                    Map p = feeDuesDetails.get(feeHead);
                                    int previousAmount = (Integer) p.get(TAG_AMOUNT);
                                    int upDateAmount = previousAmount + amount;
                                    feeDuesDetails.get(feeHead).put(TAG_AMOUNT, upDateAmount);
                                } else {
                                    totalBalanceAmount = totalBalanceAmount + amount;
                                    map = new HashMap();
                                    map.put(TAG_AMOUNT, amount);
                                    feeDuesDetails.put(feeHead, map);
                                }
                            }
                        }


                    }

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


            return null;

        }
        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            progressDialog.dismiss();
            if(checkSeverResponse) {
                if (feeDuesDetails.size() > 1) {
                    Set keys = feeDuesDetails.keySet();
                    for (Iterator i = keys.iterator(); i.hasNext(); ) {
                        String key = (String) i.next();
                        feeHead.add(key);
                        Map map = feeDuesDetails.get(key);
                        int feeHeadWiseAmount = (Integer) map.get(TAG_AMOUNT);
                        feeAmount.add(feeHeadWiseAmount);
                    }
                    feeDuesAdapter = new FeeDuesAdapter(getActivity(), feeHead, feeAmount);
                    feeDuesList.setAdapter(feeDuesAdapter);
                   totalAmountInRs.setText(String.valueOf(totalBalanceAmount));
                    paybleAmount.setText("Total Payable Amount");


                }
                else {
                    Toast.makeText(getActivity(), "Your fee paid up to this month", Toast.LENGTH_LONG).show();
                }
            }
            else {
                Toast.makeText(getActivity(), "Server not response", Toast.LENGTH_LONG).show();
            }
        }

我想要在我的片段中检索到 doInBackground 方法变量中的所有值，例如费用代码、费用头、周期等

Answer 1

你是什么意思？要从 Asynctask 中获取对象，您必须在 do inbackground() 中返回一个值。为此，您必须在对象（模型）中解析 JSON，以便返回费用对象。一旦你有了这个，你必须在加载数据时更新你的用户界面。

Answer 2

AsyncTask 为其定义了三个参数：

异步任务使用的三种类型如下：

1. Params，执行时发送给任务的参数类型。
2. 进度，进度单位在期间发布的类型 后台计算。
3. 结果，结果的类型 后台计算。

通过谷歌文档进行澄清： http://developer.android.com/reference/android/os/AsyncTask.html

您可以通过以下方式实现：

处理此类事情的接口：

public interface MyListener{
     public void onTaskComplete(int status, String data);
}

然后是你的异步任务

public class MyAsyncTask extends AsyncTask<Void, Void, String>{

    MyListener mMyListener;
    public MyAsyncTask(MyListener myListener){
         mMyListener = myListener;
    }
    ...
    public String doInBackground(Void... params){
         String valueToReturn;
         //Your code here to get the required data to set the "valueToRetun"
         return valueToReturn;
    }
    ...
    public void onPostExecute(String data){ <- you get that data here
         //Your code here
         mMyListener.onTaskComplete(1, data); <- 1  being the success status
    }
}

让你的活动实现监听器：

public class MyActivity implements MyLisntener{
     ...Your code here
     public void startTask(){
          MyAsyncTask mt = new MyAsyncTask(this);
          mt.execute();
     }

     @Override
     public void onTaskComplete(String data){
          //Process your data here
     }

     ...Your code here
}

我假设您需要返回字符串。如果您期望异步任务返回其他内容，请将其替换为您的模态对象。

希望对你有帮助:)