Android - android.os.NetworkOnMainThreadException

Question

我有这个异常(exception)，我正在阅读一个关于这个的线程，它看起来很困惑:

How to fix android.os.NetworkOnMainThreadException?

我已经将此行添加到我的 list 中:

<uses-permission android:name="android.permission.INTERNET" />

在那次讨论中，他们谈到了应用程序的主执行线程无法进行联网。我想知道的是如何重组我的代码，使其符合 Android 的良好实践。

这是我的 Activity 类:

package com.problemio;

import java.io.InputStream;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
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 android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class LoginActivity extends Activity 
{
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        // Show form for login_email
        final EditText loginEmail = (EditText) findViewById(R.id.login_email);  
        String name = loginEmail.getText().toString();  

        // Show field for password  
        final EditText password = (EditText) findViewById(R.id.password);  
        String text = password.getText().toString();                  

        // Show button for submit
        Button submit = (Button)findViewById(R.id.submit);   




        // Show options for create-profile and forgot-password




        submit.setOnClickListener(new Button.OnClickListener() 
        {  
           public void onClick(View v) 
           {
              String email = loginEmail.getText().toString();
              String pass = password.getText().toString(); 
              sendFeedback(pass, email);
            }
        });        
    }


    public void sendFeedback(String pass , String email) 
    {  
        Log.d( "1" , pass );
        Log.d( "1" , email );

        // Go to db and check if these r legit
        // How do I do that? :)
        ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();  
        postParameters.add(new BasicNameValuePair("username", email ));  
        postParameters.add(new BasicNameValuePair("password", pass ));

        String responseString = null;

        try 
        {  
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("myUrl");

            // no idea what this does :)
            httppost.setEntity(new UrlEncodedFormEntity(postParameters));

            // This is the line that send the request
            HttpResponse response = httpclient.execute(httppost);

            HttpEntity entity = response.getEntity();            

            InputStream is = entity.getContent();
        } 
        catch (Exception e) 
        {     
            Log.e("log_tag", "Error in http connection "+e.toString());
        }        
    }          
}

我在这里做错了什么，我该如何解决？ :) 谢谢!!

Answer 1

NetworkOnMainThreadException:当应用程序尝试在其主线程上执行网络操作时引发的异常。

您应该在 asynctask 上调用 sendfeedback 方法，然后只有上面的代码才能工作。由于网络服务器需要大量时间来响应主线程变得无响应。为避免它，您应该在另一个线程上调用它。因此 asynctask 更好。

这里是 link这说明了如何使用 asynctask