Question

我正在尝试开发一个Android应用程序，它将使用wifi与其他设备通信，当我运行我的代码时，它给了我networkOnMainThread异常。不明白我的代码有什么问题。这是主类Code。 package com.example.sarwa.wifimessage;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
    EditText textOut;
    TextView textIn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textOut = (EditText)findViewById(R.id.textout);
        Button buttonSend = (Button)findViewById(R.id.send);
        textIn = (TextView)findViewById(R.id.textin);
        buttonSend.setOnClickListener(buttonSendOnClickListener);
    }
    Button.OnClickListener buttonSendOnClickListener
            = new Button.OnClickListener(){

        @Override
        public void onClick(View arg0) {
            Socket socket = null;
            DataOutputStream dataOutputStream = null;
            DataInputStream dataInputStream = null;

            try {
                socket = new Socket("192.168.1.3", 8888);
                //192.168.56.1
               // 192.168.1.2
                //192.168.1.101
                dataOutputStream = new DataOutputStream(socket.getOutputStream());
                dataInputStream = new DataInputStream(socket.getInputStream());
                dataOutputStream.writeUTF(textOut.getText().toString());
                textIn.setText(dataInputStream.readUTF());
            } catch (UnknownHostException e) {
                e.printStackTrace();
                Toast.makeText(getBaseContext(), "Error1 = " + e, Toast.LENGTH_SHORT).show();
            } catch (IOException e) {
                e.printStackTrace();
                Toast.makeText(getBaseContext(), "Error2 = " + e, Toast.LENGTH_SHORT).show();
            }
            catch(Exception ex){
                Toast.makeText(getBaseContext(), "Error0 = " + ex, Toast.LENGTH_SHORT).show();
            }
            finally{
                if (socket != null){
                    try {

                        socket.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                        Toast.makeText(getBaseContext(), "Error3 = " + e, Toast.LENGTH_SHORT).show();
                    }
                }

                if (dataOutputStream != null){
                    try {
                        dataOutputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                        Toast.makeText(getBaseContext(), "Error4 = " + e, Toast.LENGTH_SHORT).show();
                    }
                }

                if (dataInputStream != null){
                    try {
                        dataInputStream.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        Toast.makeText(getBaseContext(), "Error5 = " + e, Toast.LENGTH_SHORT).show();
                    }
                }
            }
        }};



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

这是清单代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sarwa.wifimessage" >
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Here is the XML code for main class



 <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >
        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Hello PASHA"
            />
        <EditText
            android:id="@+id/textout"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            />
        <Button
            android:id="@+id/send"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Send"
            />
        <TextView
            android:id="@+id/textin"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            />
    </LinearLayout>

Answer 1

您不应该在主线程上进行网络调用。使用AsycTask或为该

启动一个不同的线程

实现套接字编程时出现networkOnMainThread异常

1 个答案: