Android更新UI的五种方式

• handler.post
• activity.runOnUiThread
• view.post
• handler+Thread
• AsyncTask

例子：

package com.chao.updateui;

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

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener{
    private Layout layout;
    private Handler handler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initLayout();
        initValue();
    }
    
    private void initLayout(){
        layout=new Layout();
        layout.helloText=(TextView) findViewById(R.id.helloText);
        layout.webImg=(ImageView) findViewById(R.id.webImg);
        layout.button1=(Button) findViewById(R.id.button1);
        layout.button2=(Button) findViewById(R.id.button2);
        layout.button3=(Button) findViewById(R.id.button3);
        layout.button4=(Button) findViewById(R.id.button4);
        layout.button5=(Button) findViewById(R.id.button5);
        layout.button1.setOnClickListener(this);
        layout.button2.setOnClickListener(this);
        layout.button3.setOnClickListener(this);
        layout.button4.setOnClickListener(this);
        layout.button5.setOnClickListener(this);
    }
    
    private void initValue(){
        layout.button1.setText("1.Handler.post");
        layout.button2.setText("2.activity.runOnUiThread");
        layout.button3.setText("3.view.post");
        layout.button4.setText("4.handler+Thread");
        layout.button5.setText("5.AsyncTask");
    }
    
    private class Layout{
        TextView helloText;
        ImageView webImg;
        Button button1;
        Button button2;
        Button button3;
        Button button4;
        Button button5;
    }

    //1.Handler.post
    private void method_1(){
        new Handler().postDelayed(new Runnable() {
            
            @Override
            public void run() {
                layout.helloText.setText("Handler的postDelayed延时一秒");
            }
        }, 1000);
    }
    //2.activity.runOnUiThread
    private void method_2(){
        new Thread(new Runnable() {
            
            @Override
            public void run() {
                try {
                    Thread.sleep(1000);
                    runOnUiThread(new Runnable() {
                        
                        @Override
                        public void run() {
                            layout.helloText.setText("在子线程中使用activity.runOnUiThread");
                        }
                    });
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    //3.view.post
    private void method_3(){
        new Thread(new Runnable() {
            
            @Override
            public void run() {
                try {
                    Thread.sleep(1000);
                    layout.helloText.post(new Runnable() {
                        
                        @Override
                        public void run() {
                            layout.helloText.setText("在子线程中使用TextView.post");
                        }
                    });
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    //4.Handler+Thread
    private void method_4(){
        handler=new Handler(){
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                if(msg.what==1){
                    Bundle bundle=msg.getData();
                    String name=bundle.getString("name");
                    String sex=bundle.getString("sex");
                    String age=bundle.getString("age");
                    layout.helloText.setText(name+"
"+sex+"
"+age);
                }
            }
        };
        Thread thread=new Thread(new Runnable() {
            
            @Override
            public void run() {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                Message msg=Message.obtain();
                msg.what=1;
                
                Bundle bundle=new Bundle();
                bundle.putString("name", "张三");
                bundle.putString("sex", "男");
                bundle.putString("age", "16");
                msg.setData(bundle);
                
                handler.sendMessage(msg);
            }
        });
        thread.start();
    }
    //5.AsyncTask
    private void method_5(){        
        AsyncTask<String, Integer, Bitmap> async=new AsyncTask<String, Integer, Bitmap>(){
            @Override
            protected Bitmap doInBackground(String... params) {
                publishProgress(0);
                HttpClient client = new DefaultHttpClient();
                HttpGet get = new HttpGet(params[0]);
                publishProgress(30);
                final Bitmap bitmap;
                try {
                    HttpResponse response = client.execute(get);
                    bitmap = BitmapFactory.decodeStream(response.getEntity()
                            .getContent());
                } catch (Exception e) {
                    return null;
                }
                publishProgress(100);
                return bitmap;
            }
            @Override
            protected void onProgressUpdate(Integer... values) {
                super.onProgressUpdate(values);
                layout.helloText.setText("进度-"+values[0]+"%");
            }
            @Override
            protected void onPostExecute(Bitmap result) {
                super.onPostExecute(result);
                if(result==null){
                    layout.helloText.setText("获取图片失败");
                }else{
                    layout.helloText.setText("获取图片成功");
                    layout.webImg.setImageBitmap(result);
                }
            }
            @Override
            protected void onPreExecute() {
                layout.webImg.setImageBitmap(null);
            }
            
        };        
        async.execute("http://imgsize.ph.126.net/?imgurl=http://img2.ph.126.net/-RloZHuMn-ultOW_YDF5fQ==/"
                + "6608648723609095427.jpg_96x96x0x90.jpg");        
    }


    @Override
    public void onClick(View v) {
        switch(v.getId()){
        case R.id.button1:
            method_1();
            break;
        case R.id.button2:
            method_2();
            break;
        case R.id.button3:
            method_3();
            break;
        case R.id.button4:
            method_4();
            break;
        case R.id.button5:
            method_5();
            break;
        default:
            break;
        }
    }
}

完整demo：http://pan.baidu.com/s/1eQcUV0Q