Handler和Message(一)

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 org.apache.http.util.EntityUtils;import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;public class HandlerActivity extends Activity {private Button button &＃61; null;private ImageView imageView &＃61; null;private String image_path &＃61; "http://11.203.18.14:8080/image/001.png";private ProgressDialog dialog &＃61; null;private static final int IS_FINISH &＃61; 1;private Handler handler &＃61; new Handler(){&＃64;Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubbyte[] data &＃61; (byte[])msg.obj;Bitmap bm &＃61; BitmapFactory.decodeByteArray(data, 0, data.length);imageView.setImageBitmap(bm);if(msg.what &＃61;&＃61; IS_FINISH){dialog.dismiss();}}};&＃64;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);button &＃61; (Button)findViewById(R.id.button1);imageView &＃61; (ImageView)findViewById(R.id.imageView1);dialog &＃61; new ProgressDialog(HandlerActivity.this);dialog.setTitle("提示");dialog.setMessage("正在下载,请稍后......");dialog.setCancelable(false);button.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {// TODO Auto-generated method stubnew Thread(new MyThread()).start();}});}//重新定义一个线程public class MyThread implements Runnable{&＃64;Overridepublic void run() {// TODO Auto-generated method stubHttpClient httpClient &＃61; new DefaultHttpClient();HttpGet httpGet &＃61; new HttpGet(image_path);HttpResponse httpResponse &＃61; null;
// InputStream inputStream &＃61; null;try{httpResponse &＃61; httpClient.execute(httpGet);if(httpResponse.getStatusLine().getStatusCode()&＃61;&＃61;200){byte[] data &＃61; EntityUtils.toByteArray(httpResponse.getEntity());Message message &＃61; Message.obtain();message.obj &＃61; data;message.what &＃61; IS_FINISH;handler.sendMessage(message);}}catch(Exception e){e.printStackTrace();}}}&＃64;Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.handler, menu);return true;}}

2. main.xml文件

3. 注册文件添加网络连接