handler与asynctask对比

package async_demo;

import com.exercise.R;
import com.exercise.R.layout;
import com.exercise.R.menu;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ProgressBar;
import android.widget.TextView;

public class AsyncTask_Handler extends Activity {
   TextView asynctask_textView;
   TextView handler_textview;
   MyHandler handler;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.async_task);
		asynctask_textView=(TextView) findViewById(R.id.asynctask_textview);
		asynctask_textView.setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Asynctask task=new Asynctask();
				task.execute();
			}
			
		});
		
		handler_textview=(TextView) findViewById(R.id.handler_textview);
		handler_textview.setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				handler=new MyHandler();
				MyThread mt=new MyThread();
				new Thread(mt).start();
			}});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.async_task, menu);
		return true;
	}
    class Asynctask extends AsyncTask<String, ProgressBar, String>{

		@Override
		protected String doInBackground(String... params) {
			// TODO Auto-generated method stub
			String text="AsynacTask_Change";
			return text;
		}

		@Override
		protected void onCancelled(String result) {
			// TODO Auto-generated method stub
			super.onCancelled(result);
		}

		@Override
		protected void onPostExecute(String result) {
			// TODO Auto-generated method stub
			asynctask_textView.setText(result);
//在asynctask中修改UI
		}

		@Override
		protected void onProgressUpdate(ProgressBar... values) {
			// TODO Auto-generated method stub
			super.onProgressUpdate(values);
		}	
    }
    class MyHandler extends Handler{

		@Override
		public void handleMessage(Message msg) {
			// TODO Auto-generated method stub
			super.handleMessage(msg);
            if (msg.what==1010){
            	Bundle b=msg.getData();
            	String textString =b.getString("text");
            	AsyncTask_Handler.this.handler_textview.setText(textString);
//在handler中修改ui
            };
		} 	
    }
    
    class MyThread implements Runnable{

		@Override
		public void run() {
			// TODO Auto-generated method stub
			Message msg=new Message();
			Bundle bundle=new Bundle();
			bundle.putString("text","Change" );
			msg.setData(bundle);
			msg.what=1010;
			AsyncTask_Handler.this.handler.sendMessage(msg);
		}
    	
    }
}