主活动中我的安卓代码错误

Question

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java .lang.String;

import static android.support.v7.appcompat.R.id.text;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView text = (TextView) findViewById(R.id.tv);
        Button btn = (Button) findViewById(R.id.btn_hit);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Jsontask().execute("https://jsonparsingdemo-cec5b.firebaseapp.com/jsonData/moviesDemoItem.txt");
            }
        });
    }
        public class Jsontask extends AsyncTask<String,String,String>{
            @Override
            protected String doInBackground(String... params) {
                HttpURLConnection http=null;
                BufferedReader reader = null;
                try {
                    URL url=new URL(params[0]);
                    http=(HttpURLConnection)url.openConnection();
                    http.connect();
                    InputStream inp=http.getInputStream();
                    reader=new BufferedReader(new InputStreamReader(inp));

                    String line=" ";
                    StringBuffer read=new StringBuffer();
                    while((line=reader.readLine())!=null)
                        read.append(line);
                    return reader.toString();
                } catch(MalformedURLException e1){
                    e1.printStackTrace();

                } catch (IOException e) {
                    e.printStackTrace();
                }
                finally {
                    if (http != null)
                        http.disconnect();
                    try {
                        if(reader!=null)
                            reader.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
             return null;
            }
            @Override
           protected void onPostExecute(String result){
                super.onPostExecute(result);
                text.setText(result);
            }
        }
        }

Answer 1

我认为问题出在以下行上：

import static android.support.v7.appcompat.R.id.text;

当您在此处设置文本时：

text.setText(result);

此文本不引用文本视图文本。因此，请检查一次此内容，如果它正确引用它。

Answer 2

TextView text = (TextView) findViewById(R.id.tv);

"text">是局部变量，所以异步任务找不到它

请在onCreate()之外定义它