Question

我正在使用Handler从主线程接收消息。但是当主线程调用方法（threadmsg）时，Handler为NULL但已创建Handler。我的代码：

package com.example.smsnotify;

import java.io.PrintWriter;

import java.net.Socket;

import com.androidexample.broadcastreceiver.R;

import android.app.Activity;

import android.content.Intent;
import android.os.Bundle;  
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;

public class MainActivity extends Activity {

private static final String TAG = "Debug";
Looper mLooper;
Handler handler=null;
Message msg;

public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";

public void threadMsg(String msg) {

    Log.i(TAG,"Before sending msg1");
    if (!msg.equals(null) && !msg.equals("")) {
        if(handler==null)
         {
          Log.i(TAG,"NULL handler");    
         }
        Message msgObj = handler.obtainMessage();
        Log.i(TAG,"Before sending msg2");
        Bundle b = new Bundle();
        b.putString("message", msg);
        msgObj.setData(b);
        Log.i(TAG,"Before sending msg3");
        handler.sendMessage(msgObj);
     }
   }

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Thread background = new Thread(new Runnable() {
        // After call for background.start this run method call
   public void run() {
   try {
        //threadMsg(SetServerString);
    Looper.prepare();
    Log.i(TAG,"New handler created");
      handler = new Handler() {
       public void handleMessage(Message msg) {
         Socket client;

     PrintWriter printwriter;
     String aResponse = msg.getData().getString("message");
           Log.i(TAG,"Got new msg:"+aResponse);

           }
    };
   } catch (Throwable t) {
                // just end the background thread
         Log.i("Debug", "Thread  exception " + t);
   }
   Looper.loop();
 }
 });
background.start();  

 finish();
    //image = (ImageView)findViewById(R.id.imageView1);
    //image.setImageResource(R.drawable.globe);
}

/** Called when the user clicks the Send button */
}

收到短信后，我从其他Android代码调用threadmsg函数。在那种情况下我得到“处理程序NULL”登录logcat。这段代码有什么问题？有谁可以帮助我？

其他Android代码我正在调用此函数：

 package com.example.smsnotify;

 import java.io.IOException;
 import java.io.PrintWriter;
 import java.net.Socket;
 import java.net.UnknownHostException;
 import android.content.*;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
 import android.telephony.*;
 import android.util.Log;
 import android.widget.Toast;

 public class IncomingSms extends BroadcastReceiver{
private static final String TAG = "Debug";
@Override
public void onReceive(Context context, Intent intent) {
    // TODO Auto-generated method stub
     Log.i(TAG,"onreceive called");
         // Create Inner Thread Class

    MainActivity mac=new MainActivity();
    Log.i(TAG,"got sms");
    Bundle pudsBundle = intent.getExtras();
     Object[] pdus = (Object[]) pudsBundle.get("pdus");
     SmsMessage messages =SmsMessage.createFromPdu((byte[]) pdus[0]);    
     Log.i(TAG,  messages.getMessageBody());
     Toast.makeText(context, "SMS Received : "+messages.getMessageBody(),
     Toast.LENGTH_LONG).show();
     mac.threadMsg(messages.getMessageBody());

     //msg = mHandler.obtainMessage();
     //mHandler.sendEmptyMessage(2);

    // isms.inform_middleware();
 }      


    }

在android线程中使用handler

0 个答案: