java - Android - 单击按钮时使用 AsyncTask 发送 HTTP 请求 |委托(delegate)问题

Question

我即将编写一个小应用程序。单击按钮后，我在自定义异步任务类中发送 http 请求。我想将此值写入 EditText 字段和 ListView 作为项目。我现在的问题是我想将请求的值返回到主线程以进一步处理它。我四处搜寻，发现了一个带有接口(interface)的方法。这是我的 asynctask 类:

    public class Request extends AsyncTask<String,Void,String> {
    public AsyncResponse delegate=null;
    private MainActivity mAct;
    public Request(MainActivity mainActivity){
        this.mAct = mainActivity;
    }
    @Override
    protected String doInBackground(String... url){
        String returnString = "";
        try {
            URL u = new URL(url[0]);
            final HttpURLConnection connection = (HttpURLConnection)u.openConnection();
            BufferedInputStream bis = new BufferedInputStream(connection.getInputStream());
            byte[] content = new byte[1024];
            int bytesRead = 0;
            String strContent = "";
            while((bytesRead = bis.read(content)) != -1){
                strContent += new String(content,0,bytesRead);
            }
            returnString = strContent;
        } catch (Exception e){

        } finally {
            return returnString;
        }
    }
    protected void onPostExecute(String result){
        delegate.processFinish(result);
    }
}

这是我的主要 Activity :

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final Button btnSend = (Button)findViewById(R.id.btnSendMessage);
    final ListView lv = (ListView)findViewById(R.id.treeView);
    final EditText editText = (EditText)findViewById(R.id.txtReqID);

    final MainActivity ma = this;
    final ArrayList<String> arrList = new ArrayList<String>();
    final ArrayAdapter<String> arrAdapter = new ArrayAdapter<String>(getApplicationContext(),R.layout.simple_list_item_1,arrList);

    btnSend.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v){
            String t = new String("http://myhttprequest");
            Request r = new Request(ma);
            public void onCreate(Bundle savedInstanceState){
                r.delegate = this;
            }

            editText.setText(returnValue);
            lv.setAdapter(arrAdapter);
            arrList.add(returnValue);
            arrAdapter.notifyDataSetChanged();
        }
    });
}
public interface AsyncResponse{
    void processFinish(String output);
}

问题是我必须将每个变量声明为final，因为我在函数中访问它们。我现在对我的代码不太满意，我也不知道如何才能完成这项工作。非常感谢任何帮助。

致以诚挚的问候

Answer 1

试试这个方法:

 btnSend.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v){
           String t = new String("http://myhttprequest");
           Request r = new Request(ma){
               protected void onPostExecute(String result){
                   editText.setText(result);
                   lv.setAdapter(result);
                   arrList.add(result);
                   arrAdapter.result();
               }
          };

     }
});