
界面中有三个控件,一个EditText,一个Button,一个ImageView
1、下面是具体布局文件
<EditText
  android:id="@+id/picturepagh"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="@string/hello_world" 
/>
<Button
  android:id="@+id/btn"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="查看" 
/>
<ImageButton
  android:id="@+id/imageView"
  android:layout_width="fill_parent"
  android:layout_height="200px" 
/>
2、在MainActivity中进行图片图示代码编写
public class MainActivity extends Activity {
 private Button 
btn;
 private EditText path;
 private ImageView imgview;
 @Override
 protected void onCreate(Bundle savedInstanceState) 
{
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  btn 
= (Button) findViewById(R.id.btn);
  path = (EditText) 
findViewById(R.id.picturepagh);
  imgview = (ImageView) 
findViewById(R.id.imageView);
  btn.setOnClickListener(new OnClickListener() {
   @Override
   public 
void onClick(View v) {
    Log.i("CLICK", ((Button) 
v).getText().toString());
    new 
Thread(runa).start();
   }
  });
 }
 public void setView() {
  String picturepath = 
path.getText().toString();
  byte[] data = null;
  try {
   data = 
ImageService.getImage(picturepath);
   Bitmap bitmap = 
BitmapFactory.decodeByteArray(data, 0, data.length);// 
BitmapFactory:图片工厂!
   Looper.prepare();// 必须调用此方法,要不然会报错
   Message msg = 
new Message();
   msg.what = 0;
   msg.obj = 
bitmap;
   handler.sendMessage(msg);
  } catch (Exception e) 
{
   Toast.makeText(getApplicationContext(), "获取图片错误", 
1).show();
  }
 }
 private Handler handler = new Handler() {
  @Override
  public void 
handleMessage(Message msg) {
   if (msg.what == 0) 
{
    updateImageView((Bitmap) msg.obj);
   }
  }
};
 private Runnable runa = new Runnable() {
  @Override
  public void 
run() {
   setView();
  }
 };
 private void updateImageView(Bitmap bm) 
{
  imgview.setImageBitmap(bm);
 }
}
3、添加一个ImageService图片服务类,里面包含一个获取网络数据的方法;
public class ImageService {
 // 获取网络图片的数据
 public static byte[] getImage(String picturepath) throws 
Exception {
  URL url = new URL(picturepath);
  HttpURLConnection conn = 
(HttpURLConnection) url.openConnection();// 
基于http协议的连接对象
  conn.setConnectTimeout(10);// 
10秒;
  conn.setRequestMethod("GET");// 大写
  if (conn.getResponseCode() == 
200) {
   InputStream ins = conn.getInputStream();
   return 
StreamTool.read(ins);
  }
  return null;
 }
}
4、添加一个流处理工作类StreamTool
public class StreamTool {
 public static byte[] read(InputStream ins) throws Exception 
{
  ByteArrayOutputStream outstream = new 
ByteArrayOutputStream();
  byte[] buffer = new byte[1024];
  int length = 
0;
  while ((length = ins.read(buffer)) > -1) 
{
   outstream.write(buffer, 0, 
length);
  }
  outstream.close();
  return 
outstream.toByteArray();
 }
}
5、大功告成?NO,还要添加网络访问权限: <uses-permission android:name="android.permission.INTERNET" />
OK,运行程序!
原文:http://www.cnblogs.com/zhengyuqi/p/4652603.html