Activity.runOnUiThread( Runnable )

View.post( Runnable )

View.postDelayed( Runnable, long )

Hanlder

AsyncTask(推荐使用)

package org.unique.async;   
import java.io.ByteArrayOutputStream;   
import java.io.InputStream;   
import java.util.ArrayList;   

import org.apache.http.HttpEntity;   
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.app.ProgressDialog;   
import android.content.Context;   
import android.content.DialogInterface;   
import android.os.AsyncTask;   
import android.os.Bundle;   
import android.os.Handler;   
import android.os.Message;   
import android.view.View;   
import android.widget.Button;   
import android.widget.EditText;   
import android.widget.TextView;   

public class NetworkActivity extends Activity{   
    private TextView message;   
    private Button open;   
    private EditText url;   

    @Override   
    public void onCreate(Bundle savedInstanceState) {   
       super.onCreate(savedInstanceState);   
       setContentView(R.layout.network);   
       message= (TextView) findViewById(R.id.message);   
       url= (EditText) findViewById(R.id.url);   
       open= (Button) findViewById(R.id.open);   
       open.setOnClickListener(new View.OnClickListener() {   
           public void onClick(View arg0) {   
              connect();   
           }   
       });   

    }   

    private void connect() {   
        PageTask task = new PageTask(this);   
        task.execute(url.getText().toString());   
    }   

    class PageTask extends AsyncTask<String, Integer, String> {   
        // 可变长的输入参数，与AsyncTask.exucute()对应   
        ProgressDialog pdialog;   
        public PageTask(Context context){   
            pdialog = new ProgressDialog(context, 0);      
            pdialog.setButton("cancel", new DialogInterface.OnClickListener() {   
             public void onClick(DialogInterface dialog, int i) {   
              dialog.cancel();   
             }   
            });   
            pdialog.setOnCancelListener(new DialogInterface.OnCancelListener() {   
             public void onCancel(DialogInterface dialog) {   
              finish();   
             }   
            });   
            pdialog.setCancelable(true);   
            pdialog.setMax(100);   
            pdialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);   
            pdialog.show();   

        }   
        @Override   
        protected String doInBackground(String... params) {   

            try{   

               HttpClient client = new DefaultHttpClient();   
               // params[0]代表连接的url   
               HttpGet get = new HttpGet(params[0]);   
               HttpResponse response = client.execute(get);   
               HttpEntity entity = response.getEntity();   
               long length = entity.getContentLength();   
               InputStream is = entity.getContent();   
               String s = null;   
               if(is != null) {   
                   ByteArrayOutputStream baos = new ByteArrayOutputStream();   

                   byte[] buf = new byte[128];   

                   int ch = -1;   

                   int count = 0;   

                   while((ch = is.read(buf)) != -1) {   

                      baos.write(buf, 0, ch);   

                      count += ch;   

                      if(length > 0) {   
                          // 如果知道响应的长度，调用publishProgress（）更新进度   
                          publishProgress((int) ((count / (float) length) * 100));   
                      }   

                      // 让线程休眠100ms   
                      Thread.sleep(100);   
                   }   
                   s = new String(baos.toByteArray());              }   
               // 返回结果   
               return s;   
            } catch(Exception e) {   
               e.printStackTrace();   

            }   

            return null;   

        }   

        @Override   
        protected void onCancelled() {   
            super.onCancelled();   
        }   

        @Override   
        protected void onPostExecute(String result) {   
            // 返回HTML页面的内容   
            message.setText(result);   
            pdialog.dismiss();    
        }   

        @Override   
        protected void onPreExecute() {   
            // 任务启动，可以在这里显示一个对话框，这里简单处理   
            message.setText(R.string.task_started);   
        }   

        @Override   
        protected void onProgressUpdate(Integer... values) {   
            // 更新进度   
              System.out.println(""+values[0]);   
              message.setText(""+values[0]);   
              pdialog.setProgress(values[0]);   
        }   

     }   

}