Android 3.0 访问WebService 出现 android.os.NetworkOnMainThreadException异常

以前用2.2 访问WebService没有问题，到3.0上访问出现android.os.NetworkOnMainThreadException
找了资料经过实践，解决方法是在activity类中的onCreate方法中添加strict代码，如下：
 
Java代码  收藏代码

public void onCreate() {         .......       StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()                   .detectDiskReads()                   .detectDiskWrites()                   .detectNetwork()   // or .detectAll() for all detectable problems                   .penaltyLog()                   .build());            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()                   .detectLeakedSqlLiteObjects()                .penaltyLog()                   .penaltyDeath()                   .build());         ......  }     

 
似乎是3.0在网络上做了更加严格的限制

package org.sword.android;import java.util.ArrayList;import java.util.List;import org.apache.http.HttpResponse;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;import org.apache.http.protocol.HTTP;import org.apache.http.util.EntityUtils;import android.app.Activity;import android.os.Bundle;import android.os.StrictMode;import android.widget.Button;public class InternetActivity extends Activity {   private static final String SERVER_UTL = "http://www.webservicex.net/WeatherForecast.asmx/GetWeatherByZipCode";private Button button;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()        .detectDiskReads()        .detectDiskWrites()        .detectNetwork()   // or .detectAll() for all detectable problems        .penaltyLog()        .build());        StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()        .detectLeakedSqlLiteObjects()        .detectLeakedClosableObjects()        .penaltyLog()        .penaltyDeath()        .build());        getWeather();    }        private void getWeather(){        try {                final String SERVER_URL = "http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx/getWeather"; // 定义需要获取的内容来源地址                HttpPost request = new HttpPost(SERVER_URL); // 根据内容来源地址创建一个Http请求                List params = new ArrayList();                params.add(new BasicNameValuePair("theCityCode", "长沙")); // 添加必须的参数                params.add(new BasicNameValuePair("theUserID", "")); // 添加必须的参数                request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8)); // 设置参数的编码                HttpResponse httpResponse = new DefaultHttpClient().execute(request); // 发送请求并获取反馈                // 解析返回的内容                if (httpResponse.getStatusLine().getStatusCode() != 404)                {                        String result = EntityUtils.toString(httpResponse.getEntity());                        System.out.println("result =" + result);                }        } catch (Exception e) {        e.printStackTrace();        }}}