package com.example.day9;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 org.apache.http.util.EntityUtils;import android.app.Activity;import android.app.Dialog;import android.app.ProgressDialog;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.AsyncTask;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ImageView;public class MainActivity extends Activity {    private Button bt1;    private ProgressDialog dialog;    private String url="http://b.hiphotos.baidu.com/image/w%3D2048/sign=0240c37eb0119313c743f8b051000dd7/e4dde71190ef76c6f6ecf6979f16fdfaaf51674b.jpg";    private ImageView imageView;        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        this.imageView=(ImageView)super.findViewById(R.id.iv);        this.dialog=new ProgressDialog(this);        this.dialog.setTitle("提示框");        this.dialog.setMessage("正在下载图片..");         this.bt1=(Button)super.findViewById(R.id.bt1);        this.bt1.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View arg0) {                // TODO Auto-generated method stub                new ImageDowload().execute(url);            }        });                            }     public class ImageDowload extends AsyncTask
     
      {         //第一个参数为任务，这里指的是下载链接         //第二个参数是进度，一般是Integer         //第三个参数是执行结果返回类型，这里是图片         public Bitmap doInBackground(String... arg0) {            // 耗时操作在这里执行，参数为任务类型，这里是指下载链接（String）            HttpClient client=new DefaultHttpClient();            HttpGet httpGet=new HttpGet(arg0[0]);            Bitmap bitmap=null;            Log.i("lcw", arg0[0]);            try {                HttpResponse httpResponse = client.execute(httpGet);                if(httpResponse.getStatusLine().getStatusCode()==200){                    Log.i("www", httpResponse+"");                    HttpEntity entity=httpResponse.getEntity();                    byte data[]=EntityUtils.toByteArray(entity);                    bitmap=BitmapFactory.decodeByteArray(data, 0, data.length);                    }            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }                        return bitmap;        }        @Override        public void onPostExecute(Bitmap result) {            // 最后操作，更新UI操作            super.onPostExecute(result);            Log.i("11111111", "eeee");            MainActivity.this.imageView.setImageBitmap(result);            dialog.dismiss();        }        @Override        public void onPreExecute() {            // 最早操作，预处理动作            super.onPreExecute();            MainActivity.this.dialog.show();        }                                    }}
     

效果图如下：