如何在切换片段时停止 AsyncTask？

Posted 2023-05-07

【中文标题】如何在切换片段时停止 AsyncTask？

【英文标题】：How to stop the AsyncTask while switching Fragments?

【发布时间】：2020-03-10 05:32:45

【问题描述】：

我正在使用底部导航栏，Asynctask 在切换片段时不工作，需要等待 8 到 10 分钟才能从 asynctask 获得响应。由于 Asynctask 问题，所有页面都没有数据可显示。 请帮我解决这个问题。谢谢 片段切换代码：

    private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
        = new BottomNavigationView.OnNavigationItemSelectedListener() 

    @Override
    public boolean onNavigationItemSelected( MenuItem item) 
        Fragment fragment=null;
        switch (item.getItemId()) 
            case R.id.navigation_home:
                fragment = new HomeFragment();
                break;
            case R.id.navigation_market:
                fragment=new MarketFragment();
                break;
            case R.id.navigation_agent:
                fragment=new AgentFragment();
                break;
            case R.id.navigation_finance:
                fragment=new FinanceFragment();
                break;
           /* case R.id.navigation_more:
                MoreFragment moreFragment=new MoreFragment();
                moreFragment.show(getSupportFragmentManager(),moreFragment.getTag());*/
        
        closeContextMenu();
        return loadFragment(fragment);
    
;
private boolean loadFragment(Fragment fragment) 
    if (fragment != null) 
        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.fragment_container, fragment)
                .commit();
        return true;
    
    return false;
```

异步任务代码： 我在所有片段中都实现了这样的异步任务。

        JSONObject jsonObject, jsonObject2;
        @Override
        protected void onPreExecute() 
            super.onPreExecute();
            SignupActivity.this.layoutProgress.setVisibility(View.VISIBLE);
        
        @Override
        protected String doInBackground(Void... voids) 
            HashMap<String, String> map = new HashMap<>();
            map.put("countrycode",code);
            map.put("phonenumber",phone);
            map.put("emailid",email);
            map.put("agentname",fullname);
            map.put("username",username);
            map.put("password",lpassword);
            map.put("confirmpassword",conlpassword);
            map.put("transactionpassword",spassword);
            map.put("transactionconfirmpassword",conspassword);
            return new HttpHandler().sendPostRequest(Config.url + "JoinNowRegister",map);
        
        @Override
        protected void onPostExecute(String response) 
            super.onPostExecute(response);
            Toast.makeText(getApplicationContext(), "test", Toast.LENGTH_LONG).show();
            try 
                jsonObject = new JSONObject(response);
                if(jsonObject.getString("statuscode").equals("1"))
                    message = jsonObject.getString("status");
                    jsonObject2 = jsonObject.getJSONObject("data");
                    id = jsonObject2.getString("agentid");
                    int code=Integer.parseInt(jsonObject2.getString("countrycode"));
                    String phonenumber= jsonObject2.getString("phone");
                    storeCode(code);
                    storePhone(phonenumber);
                    Intent intent;
                    intent = new Intent(SignupActivity.this, OtpActivity.class);
                    Bundle bundle = new Bundle();
                    bundle.putString("agentid",id);
                    intent.putExtras(bundle);
                    startActivity ( intent );
                    finish();
                
                else
                    msg=jsonObject.getString("data");
                    Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
                
             catch (JSONException e) 
                e.printStackTrace();
             catch (NullPointerException e) 
                e.printStackTrace();
             catch (Exception e) 
                e.printStackTrace();
            
            SignupActivity.this.layoutProgress.setVisibility(View.GONE);
        
       

【问题讨论】：

请将您的代码添加到相关问题中

【参考方案1】：

在您的片段中使用它，它将停止 AsyncTask...

@Override
protected void onDestroy() 
    super.onDestroy();
    // cancel running task(s) to avoid memory leaks
    if (runningTask != null) runningTask.cancel(true);

【参考方案2】：

使用并行执行。

 task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);