可能重复：   Strange NetworkOnMainThreadException在Android应用程序？   Trying上传到Dropbox的：NetworkOnMainThreadException

我用下面$ C $下读取URL的HTML内容。这完全适用于2.3.3，但是当我尝试运行相同的code它ICS不起作用。

我想就这些追加的HTML内容到的EditText 。但是，它始终保持空当我运行ICS的code。可能是什么问题？

 公共类Quiz1Activity延伸活动{
    私有静态的BufferedReader读卡器= NULL;
    / **第一次创建活动时调用。 * /
    @覆盖
    公共无效的onCreate（包savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.main）;

的EditText ED =（EditText上）findViewById（R.id.editText1）;

        尝试 {
            ed.append（getStringFromUrl（http://www.google.com））;
            // getInputStreamFromUrl（）关闭（）。
        }赶上（例外五）{
            // TODO自动生成的catch块
            e.printStackTrace（）;
        }
    }

    公共静态的InputStream getInputStreamFromUrl（字符串URL）{
           InputStream的contentStream = NULL;

           尝试{
             HttpClient的HttpClient的=新DefaultHttpClient（）;
             HTT presponse响应= httpclient.execute（新HTTPGET（URL））;
             contentStream = response.getEntity（）的getContent（）。
           }赶上（例外五）{
              e.printStackTrace（）;
           }
           的System.out.println（内容流为+ contentStream）;
           返回contentStream;
        }

    公共静态字符串getStringFromUrl（字符串URL）抛出IOException异常{
        读者=新的BufferedReader（新的InputStreamReader（getInputStreamFromUrl（URL）））;

        StringBuilder的SB =新的StringBuilder（）;
        尝试{
        串线= NULL;
        而（（行= reader.readLine（））！= NULL）
        {
            sb.append（线）;
        }
        }赶上（IOException异常E）{
         e.printStackTrace（）;
        }
       getInputStreamFromUrl（URL）.close（）;
        返回sb.toString（）;
    }
}
 

解决方案

就像@Vipul沙阿说你必须移动getInputStreamFromUrl（）到另一个线程使用异步任务，这是对ICS的工作：

 包com.home.anas;

进口java.io.BufferedReader中;
进口的java.io.InputStream;
进口java.io.InputStreamReader中;

进口org.apache.http.Htt presponse;
进口org.apache.http.client.methods.HttpGet;
进口org.apache.http.impl.client.DefaultHttpClient;

进口android.app.Activity;
进口android.os.AsyncTask;
进口android.os.Bundle;
进口android.widget.EditText;

公共类WebPageContentActivity延伸活动{
    私人的EditText编辑;


/ **第一次创建活动时调用。 * /

    @覆盖
    公共无效的onCreate（包savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.main）;
        ED =（EditText上）findViewById（R.id.editText1）;
        readWebpage（）;
    }

    私有类DownloadWebPageTask扩展的AsyncTask＆LT;字符串，太虚，字符串＆GT; {
        @覆盖
        保护字符串doInBackground（字符串...网址）{
            串响应=;
            对于（字符串网址：网址）{
                DefaultHttpClient客户端=新DefaultHttpClient（）;
                HTTPGET HTTPGET =新HTTPGET（URL）;
                尝试 {
                    HTT presponse执行= client.execute（HTTPGET）;
                    InputStream的内容= execute.getEntity（）的getContent（）。

                    的BufferedReader缓冲=新的BufferedReader（新InputStreamReader的（内容））;
                    字符串s =;
                    而（（S = buffer.readLine（））！= NULL）{
                        响应+ = S;
                    }

                }赶上（例外五）{
                    e.printStackTrace（）;
                }
            }
            返回响应;
        }

        @覆盖
        保护无效onPostExecute（字符串结果）{
            ed.setText（结果）;
        }
    }

    公共无效readWebpage（）{
        DownloadWebPageTask任务=新DownloadWebPageTask（）;
        task.execute（新的String [] {http://www.google.com}）;

    }
}
 

Possible Duplicate: Strange NetworkOnMainThreadException in Android app? Trying To Upload To Dropbox: NetworkOnMainThreadException?

I have used the below code for reading HTML contents from a url. This works perfectly for 2.3.3 but when I try to run the same code it doesn't work for ICS.

I am trying to append these html contents on to a edittext. But it always remains empty when I run the code on ICS. What may be the problem?

public class Quiz1Activity extends Activity {
    private static BufferedReader reader = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

EditText ed = (EditText) findViewById(R.id.editText1);

        try {
            ed.append(getStringFromUrl("http://www.google.com"));
            //getInputStreamFromUrl("").close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public static InputStream getInputStreamFromUrl(String url){
           InputStream contentStream = null;

           try{
             HttpClient httpclient = new DefaultHttpClient();
             HttpResponse response = httpclient.execute(new HttpGet(url));
             contentStream = response.getEntity().getContent();
           } catch(Exception e){
              e.printStackTrace();
           }
           System.out.println("Content stream is " + contentStream);
           return contentStream;
        }

    public static String getStringFromUrl(String url) throws IOException{
        reader = new BufferedReader(new InputStreamReader(getInputStreamFromUrl(url)));

        StringBuilder sb = new StringBuilder();
        try{
        String line = null;
        while((line = reader.readLine()) != null)
        {
            sb.append(line);
        }    
        }catch (IOException e){
         e.printStackTrace();
        }
       getInputStreamFromUrl(url).close();
        return sb.toString();
    }
}

Like @Vipul Shah said you have to move getInputStreamFromUrl() into another thread use Async Task, this is work on ICS:

package com.home.anas;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.EditText;

public class WebPageContentActivity extends Activity {
    private EditText ed;


/** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ed = (EditText) findViewById(R.id.editText1);
        readWebpage();
    }

    private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            String response = "";
            for (String url : urls) {
                DefaultHttpClient client = new DefaultHttpClient();
                HttpGet httpGet = new HttpGet(url);
                try {
                    HttpResponse execute = client.execute(httpGet);
                    InputStream content = execute.getEntity().getContent();

                    BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                    String s = "";
                    while ((s = buffer.readLine()) != null) {
                        response += s;
                    }

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

        @Override
        protected void onPostExecute(String result) {
            ed.setText(result);
        }
    }

    public void readWebpage() {
        DownloadWebPageTask task = new DownloadWebPageTask();
        task.execute(new String[] { "http://www.google.com" });

    }
}