如何在ImageView中使用URL引用的图像?


当前回答

public class LoadWebImg extends Activity {

String image_URL=
 "http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png";

   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);

       ImageView bmImage = (ImageView)findViewById(R.id.image);
    BitmapFactory.Options bmOptions;
    bmOptions = new BitmapFactory.Options();
    bmOptions.inSampleSize = 1;
    Bitmap bm = LoadImage(image_URL, bmOptions);
    bmImage.setImageBitmap(bm);
   }

   private Bitmap LoadImage(String URL, BitmapFactory.Options options)
   {       
    Bitmap bitmap = null;
    InputStream in = null;       
       try {
           in = OpenHttpConnection(URL);
           bitmap = BitmapFactory.decodeStream(in, null, options);
           in.close();
       } catch (IOException e1) {
       }
       return bitmap;               
   }

private InputStream OpenHttpConnection(String strURL) throws IOException{
 InputStream inputStream = null;
 URL url = new URL(strURL);
 URLConnection conn = url.openConnection();

 try{
  HttpURLConnection httpConn = (HttpURLConnection)conn;
  httpConn.setRequestMethod("GET");
  httpConn.connect();

  if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
   inputStream = httpConn.getInputStream();
  }
 }
 catch (Exception ex)
 {
 }
 return inputStream;
}
}

其他回答

如果你是在点击按钮的基础上加载图像,上面接受的答案是很棒的,但是如果你是在一个新的活动中做这件事,它会冻结UI一到两秒钟。环顾四周,我发现一个简单的asynctask消除了这个问题。

要使用asynctask,在activity的末尾添加这个类:

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    ImageView bmImage;

    public DownloadImageTask(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {
        String urldisplay = urls[0];
        Bitmap mIcon11 = null;
        try {
            InputStream in = new java.net.URL(urldisplay).openStream();
            mIcon11 = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return mIcon11;
    }

    protected void onPostExecute(Bitmap result) {
        bmImage.setImageBitmap(result);
    }    
}

从你的onCreate()方法调用使用:

new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
        .execute(MY_URL_STRING);

结果是一个快速加载的活动和一个稍后根据用户的网络速度显示的imageview。

在我看来,最适合完成这项任务的现代图书馆是毕加索广场图书馆。它允许通过URL加载图像到ImageView,只需一行代码:

Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);

这是一个迟到的回复,正如上面所建议的AsyncTask将会和谷歌一点后,我发现了一个解决这个问题的方法。

Drawable Drawable = Drawable. createfromstream ((InputStream) new URL(" URL ").getContent(), "src");

imageView.setImageDrawable(可拉的);

这是完整的功能:

public void loadMapPreview () {
    //start a background thread for networking
    new Thread(new Runnable() {
        public void run(){
            try {
                //download the drawable
                final Drawable drawable = Drawable.createFromStream((InputStream) new URL("url").getContent(), "src");
                //edit the view in the UI thread
                imageView.post(new Runnable() {
                    public void run() {
                        imageView.setImageDrawable(drawable);
                    }
                });
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();
}

不要忘记在你的AndroidManifest.xml中添加以下权限来访问互联网。

< uses-permission android: name = " android.permission。互联网" / >

我自己也试过,还没有遇到任何问题。

我最近在这里找到了一个线程,因为我必须为带有图像的列表视图做类似的事情,但原理很简单,正如您可以在那里显示的第一个示例类中读到的那样(由jleedev)。 你得到图像的输入流(从网络)

private InputStream fetch(String urlString) throws MalformedURLException, IOException {
    DefaultHttpClient httpClient = new DefaultHttpClient();
    HttpGet request = new HttpGet(urlString);
    HttpResponse response = httpClient.execute(request);
    return response.getEntity().getContent();
}

然后你将图像存储为可绘制的,你可以将它传递给ImageView(通过setImageDrawable)。同样从上面的代码片段来看一下整个线程。

InputStream is = fetch(urlString);
Drawable drawable = Drawable.createFromStream(is, "src");

嗨,我有最简单的代码试试这个

    public class ImageFromUrlExample extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);  
            ImageView imgView =(ImageView)findViewById(R.id.ImageView01);
            Drawable drawable = LoadImageFromWebOperations("http://www.androidpeople.com/wp-content/uploads/2010/03/android.png");
            imgView.setImageDrawable(drawable);

    }

    private Drawable LoadImageFromWebOperations(String url)
    {
          try{
        InputStream is = (InputStream) new URL(url).getContent();
        Drawable d = Drawable.createFromStream(is, "src name");
        return d;
      }catch (Exception e) {
        System.out.println("Exc="+e);
        return null;
      }
    }
   }

main。xml

  <LinearLayout 
    android:id="@+id/LinearLayout01"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">
   <ImageView 
       android:id="@+id/ImageView01"
       android:layout_height="wrap_content" 
       android:layout_width="wrap_content"/>

试试这个