无法在线程looper prepare中创建处理程序

Question

我正在努力 Run this Code Example我用自己的代码替换了readWebPage()方法。

我正在尝试在服务中实现CHAT HEADS。

Log Cat

03-10 00:22:00.309: E/AndroidRuntime(9302): FATAL EXCEPTION: Thread-596
03-10 00:22:00.309: E/AndroidRuntime(9302): Process: com.example.soc, PID: 9302
03-10 00:22:00.309: E/AndroidRuntime(9302): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.os.Handler.<init>(Handler.java:200)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.os.Handler.<init>(Handler.java:114)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.view.ViewRootImpl$ViewRootHandler.<init>(ViewRootImpl.java:2968)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.view.ViewRootImpl.<init>(ViewRootImpl.java:3248)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at com.example.soc.msgService.readWebPage(msgService.java:98)
03-10 00:22:00.309: E/AndroidRuntime(9302):     at com.example.soc.msgService$MyThread.run(msgService.java:108)

MainActivity.java

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startService(new Intent(MainActivity.this, msgService.class));
}

msgService.java

package com.example.soc;

import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;

import com.example.soc.util.ImageLoadTask;
import com.squareup.picasso.Picasso;

import android.app.Service;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.os.IBinder;
import android.util.Log;
import android.view.Gravity;
import android.view.WindowManager;
import android.widget.ImageView;

public class msgService extends Service{

    private static String TAG = msgService.class.getSimpleName();
    private MyThread mythread;
    public boolean isRunning = false;
    private WindowManager windowManager;
    private ImageView chatHead;    
    String url = "someimageurl.jpg"; 

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "onCreate");     
        mythread  = new MyThread();
    }

    @Override
    public synchronized void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy");
        if(!isRunning){
            mythread.interrupt();
            mythread.stop();
        }       
    }

    @Override
    public synchronized void onStart(Intent intent, int startId) {
        super.onStart(intent, startId); 
        Log.d(TAG, "onStart");
        if(!isRunning){
            mythread.start();
            isRunning = true;
        }
    }

    public void readWebPage(){

          windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

          chatHead = new ImageView(this);
          Picasso.with(this).load(url).into(chatHead);



          WindowManager.LayoutParams params = new WindowManager.LayoutParams(
              WindowManager.LayoutParams.WRAP_CONTENT,
              WindowManager.LayoutParams.WRAP_CONTENT,
              WindowManager.LayoutParams.TYPE_PHONE,
              WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
              PixelFormat.TRANSLUCENT);

          params.gravity = Gravity.TOP | Gravity.LEFT;
          params.x = 0;
          params.y = 100;

          windowManager.addView(chatHead, params);          
    }

    class MyThread extends Thread{
        static final long DELAY = 3000;
        @Override
        public void run(){          
            while(isRunning){
                Log.d(TAG,"Running");
                try {                   
                    readWebPage();

                    Thread.sleep(DELAY);
                } catch (InterruptedException e) {
                    isRunning = false;
                    e.printStackTrace();
                }
            }
        }

    }

}