1：androidmanifest.xml的内容

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="cn.capinftotech.image"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".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>
    <uses-sdk android:minSdkVersion="8" />
    <uses-permission android:name="android.permission.INTERNET" />

</manifest>

注意访问网络中的数据需要添加android.permission.INTERNET权限

2：MainActivity的内容

package cn.capinftotech.image;

import java.io.IOException;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import com.capinfotech.service.ImageService;

public class MainActivity extends Activity {
    private static final String TAG = "MainActivity";
    
    private EditText urlPath = null;
    private Button button = null;
    private ImageView imageView = null;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        urlPath = (EditText)findViewById(R.id.urlpath);
        button = (Button)findViewById(R.id.button);
        imageView = (ImageView)findViewById(R.id.imageView);
        
        button.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                String urlPathContent = urlPath.getText().toString();
                try {
                    byte[] data = ImageService.getImage(urlPathContent);
                    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);  //生成位图
                    imageView.setImageBitmap(bitmap);   //显示图片
                } catch (IOException e) {
                    Toast.makeText(MainActivity.this, R.string.error, Toast.LENGTH_LONG).show();  //通知用户连接超时信息
                    Log.i(TAG, e.toString());
                }
                
            }
        });
    }
}


3：ImageService类的内容

package com.capinfotech.service;

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

import com.capinfotech.utils.StreamTool;

public class ImageService {
  
  public static byte[] getImage(String path) throws IOException {
    URL url = new URL(path);
    HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    conn.setRequestMethod("GET");   //设置请求方法为GET
    conn.setReadTimeout(5*1000);    //设置请求过时时间为5秒
    InputStream inputStream = conn.getInputStream();   //通过输入流获得图片数据
    byte[] data = StreamTool.readInputStream(inputStream);     //获得图片的二进制数据
    return data;
    
  }
}


4：StreamTool的内容

package com.capinfotech.utils;

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

public class StreamTool {

    /*
     * 从数据流中获得数据
     */
    public static  byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
        
    }
}


5：程序中用到的字符串资源strings.xml里的内容

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World, MainActivity!</string>
    <string name="app_name">图片浏览器</string>
    <string name="urlpath">网络图片地址</string>
    <string name="button">显示</string>
    <string name="error">网络连接超时</string>
</resources>


6：程序布局文件main.xml的内容

<?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"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/urlpath"
    />
<EditText 
    android:id="@+id/urlpath"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="http://www.eoeandroid.com/data/attachment/forum/201107/18/142935bbi8d3zpf3d0dd7z.jpg"
    />
<Button
    android:id="@+id/button"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/button"
    />
<ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
/>
</LinearLayout>


7：程序界面及测试结果

android从网络中获得一张图片，并显示在屏幕上_button