【搞错了，没看到后面的视频在onPostExecute加绑定adapter】

【MainActivity代码】

package com.example.asynctask;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.UnsupportedEncodingException;

import java.net.URL;

import java.util.ArrayList;

import java.util.List;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import android.app.Activity;

import android.os.AsyncTask;

import android.os.Bundle;

import android.widget.ListView;

public class MainActivity extends Activity {

private ListView mListView;

private static String URL = "http://www.imooc.com/api/teacher?type=4&num=30";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mListView = (ListView) findViewById(R.id.lv_main);

mListView.setAdapter(new NewsAdapter(MainActivity.this,getJsonData(URL)));

new NewAsyncTask().execute(URL);

}

// 将url//

private List<NewsBean> getJsonData(String url) {

List<NewsBean> newsBeanList = new ArrayList<>();

try {

String jsonString = readStream(new URL(url).openStream());

// logcat打印,未解析数据

// Log.d("xys",jsonString);

/* 解析JSON数据到List中 */

JSONObject jsonObject;

NewsBean newsBean;

try {

jsonObject= new JSONObject(jsonString);

JSONArray jsonArray = jsonObject.getJSONArray("data");

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

jsonObject = jsonArray.getJSONObject(i);

newsBean = new NewsBean();

newsBean.newsIconUrl = jsonObject.getString("picSmall");

newsBean.newsTitle = jsonObject.getString("name");

newsBean.newsContent = jsonObject.getString("description");

newsBeanList.add(newsBean);

}

} catch (JSONException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

} catch (IOException e) {

// TODO: handle exception

e.printStackTrace();

}

return newsBeanList;

}

private String readStream(InputStream is) {

InputStreamReader isr;

String result = "";

try {

String line = "";

isr = new InputStreamReader(is, "utf-8"); // 字节流转字符流

BufferedReader br = new BufferedReader(isr);

while ((line = br.readLine()) != null) {

result += line;

}

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

} 

return result;

}

class NewAsyncTask extends AsyncTask<String, Void, List<NewsBean>> {

@Override

protected List<NewsBean> doInBackground(String... params) {

// TODO Auto-generated method stub

return getJsonData(params[0]);

}

}

}

/*

已经排查过权限及工程其他类，觉得MainActivity存在Bug的问题比较大，故只贴了MainActivity

*/