handler从网络获取图片

来源：互联网发布：小说采集网站源码编辑：程序博客网时间：2024/05/17 06:24

package com.smalltown.day18_handlerimag;

import com.smalltown.day18_handlerimag.utils.HttpUtils;

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.View;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

   private ImageView iv;

   private static final String imagPath = "https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superplus/img/logo_white_ee663702.png";

   private ProgressDialog progressDialog;

   private static final int OK = 1;
   private static final int ERROR = OK+1;



   private Handler handler = new Handler(){
       public void handleMessage(android.os.Message msg) {

           switch (msg.what) {
           case OK:
               Bitmap bp = (Bitmap) msg.obj;
               iv.setImageBitmap(bp);
               break;
           case ERROR:
               String str = (String) msg.obj;
               Toast.makeText(MainActivity.this, str, 0).show();
               break;

           default:
               break;
           }

           progressDialog.dismiss();
       };
   };

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       iv = (ImageView) findViewById(R.id.iv);

       progressDialog = new ProgressDialog(MainActivity.this);
       progressDialog.setMessage("正在下载数据");
   }

   //点击按钮下载图片
   public void OnclickBtn(View v){



       switch (v.getId()) {
       case R.id.btn:

           progressDialog.show();

           new Thread(){
               public void run() {
                   if(HttpUtils.isNetWork(MainActivity.this)){
                       byte[] buffer = HttpUtils.getData(imagPath);
                       if(buffer!=null && buffer.length>0){
                           Bitmap bp = BitmapFactory.decodeByteArray(buffer, 0, buffer.length);
                           Message msg = handler.obtainMessage();
                           msg.obj = bp;
                           msg.what = OK;//下载成功
                           handler.sendMessage(msg);
                       }
                   }else{
                       //无网络
                       Message msg = handler.obtainMessage();
                       msg.obj = "网络异常,请检测";
                       msg.what = ERROR;//下载失败
                       handler.sendMessage(msg);

                   }

               };

           }.start();


           break;

       default:
           break;
       }

   }

}

package com.smalltown.day18_handlerimag.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

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

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class HttpUtils {
   /**
   * 判断是否有网络
   * @param context
   * @return
   */
   public static boolean isNetWork(Context context){
       //得到网络的管理者
       ConnectivityManager manager = (ConnectivityManager)
               context.getSystemService(Context.CONNECTIVITY_SERVICE);
       NetworkInfo info = manager.getActiveNetworkInfo();

       if(info!=null){
           return true;

       }else{
           return false;
       }

   }


   /**
   * 获取数据
   * @param path
   * @return
   */
   public static byte[] getData(String path) {
       HttpClient httpClient = new DefaultHttpClient();
       HttpGet httpGet = new HttpGet(path);
       ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
       try {
           HttpResponse response = httpClient.execute(httpGet);
           if (response.getStatusLine().getStatusCode() == 200) {
               InputStream inputStream = response.getEntity().getContent();
               byte[] buffer = new byte[1024];
               int temp = 0;
               while ((temp = inputStream.read(buffer)) != -1) {
                   outputStream.write(buffer, 0, temp);
                   outputStream.flush();
               }

           }
           return outputStream.toByteArray();

       } catch (ClientProtocolException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } catch (IOException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }

       return null;

   }

}

布局文件

0 0