ImageView从网络上获取图像

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    
    <ImageView android:id="@+id/imageview" 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
     <Button 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="下载网络图片"
         />
    
    
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.study.httpimageview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.study.httpimageview.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <!-- 添加访问网络的一个授权 -->
    <uses-permission android:name="android.permission.INTERNET"/>
</manifest>

package com.study.httpimageview;

import java.io.InputStream;

import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

    private Button button;
    private ImageView imageView;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button)this.findViewById(R.id.button);
        imageView = (ImageView)this.findViewById(R.id.imageview);
        button.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                /*try {
                    InputStream inputStream = HttpUtils.getImageViewInputStream();
                    Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
                    imageView.setImageBitmap(bitmap);
                } catch (Exception e) {
                    // TODO: handle exception
                }*/
                
                byte[] data = HttpUtils.getImageViewArray();
                Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
                imageView.setImageBitmap(bitmap);
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}

package com.study.httpimageview;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtils {
    
    
    public HttpUtils(){
        
    }
    /***
     * 从网络中获取图片信息，以流的形式返回
     */
    private final static String URL_PATH_STRING = "http://www.4493.com/uploads/attaches/2011/04/1302234716-EWZW9J.jpg";//访问图片的路径
    public static InputStream getImageViewInputStream()throws IOException{
        InputStream inputStream = null;
            URL url = new URL(URL_PATH_STRING);
            if(url != null){
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                httpURLConnection.setConnectTimeout(3000);//设置连接超时时间
                httpURLConnection.setRequestMethod("GET");
                httpURLConnection.setDoInput(true);
                int response_code = httpURLConnection.getResponseCode();
                if(response_code == 200){
                    inputStream = httpURLConnection.getInputStream();
                }
            }
    
        
        return inputStream;
    }
    
    /***
     * 从网络中获取图片信息，以字节数组的形式返回
     */
    public static byte[] getImageViewArray(){
        byte[] data = null;
        InputStream inputStream = null;
        //ByteArrayOutputStream不需要关闭的输出流，直接写入到内存中
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        try {
            URL url = new URL(URL_PATH_STRING);
            if(url != null){
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                httpURLConnection.setConnectTimeout(3000);//设置连接超时时间
                httpURLConnection.setRequestMethod("GET");
                httpURLConnection.setDoInput(true);
                int response_code = httpURLConnection.getResponseCode();
                int len = 0;
                byte[] b_data = new byte[1024];
                if(response_code == 200){
                    inputStream = httpURLConnection.getInputStream();
                    while((len = inputStream.read(b_data)) != -1){
                        outputStream.write(b_data,0,len);
                    }
                    data = outputStream.toByteArray();
                }
            }
        } catch (Exception e) {
            // TODO: handle exception
        }finally{
            if(inputStream != null){
                try {
                    inputStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
        
        return data;
    }
}