Question

我正在尝试将Imageview设置为来自互联网的图片

这是我的xml代码

 <ImageView
    android:id="@+id/ivget"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/bg" />

这是我的java代码

ImageView test;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.getpic);
    test = (ImageView) findViewById(R.id.ivget);

    try{
        String url1 =  "http://www.esa.int/var/esa/storage/images/esa_multimedia/images/2012/11/glitter_galaxy/12136712-1-eng-GB/Glitter_Galaxy.jpg";
        URL ulrn = new URL(url1);
        HttpURLConnection con = (HttpURLConnection)ulrn.openConnection();
        InputStream is = con.getInputStream();
        Bitmap bmp = BitmapFactory.decodeStream(is);
        if (null != bmp)
            test.setImageBitmap(bmp);
        else
            Toast.makeText(getApplicationContext(), "Null",   Toast.LENGTH_SHORT).show();

    } catch(Exception e) {
    }

}

当我运行应用程序时，imageview只与它设置的图片保持一致。如果删除imageview src，屏幕只是空白。

android清单具有Internet权限。

任何人都知道它为什么不起作用？

Answer 1

使用后台线程从互联网下载任何内容并更新UI视图。

Answer 2

您应该使用AsyncTask从服务器下载图像，如：

public class loadSingleView extends AsyncTask<String, String, String> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(SingleImageViewActivity.this);
            pDialog.setTitle("Connect to Server");
            pDialog.setMessage("This process can take a few seconds to a few minutes, depending on your Internet Connection Speed.");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }
        @Override
        protected String doInBackground(String... args) {
            // updating UI from Background Thread
            try {  
                Intent in = getIntent();

                big_image_url = in.getStringExtra(KEY_BIG_URL);
                title = in.getStringExtra(KEY_TITLE);
                artist = in.getStringExtra(KEY_ARTIST);


                url = new URL(big_image_url);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();   
                conn.setDoInput(true);   
                conn.connect();     
                InputStream is = conn.getInputStream();
                bmImg = BitmapFactory.decodeStream(is); 
            }
            catch (IOException e)
            {       
                e.printStackTrace();  
            }

            return null;   
        }
            @Override       
    protected void onPostExecute(String args) {
        // dismiss the dialog after getting all products
         TextView lblName = (TextView) findViewById(R.id.name_title);
            TextView lblCost = (TextView) findViewById(R.id.name_artist);



            lblName.setText(title);
            lblCost.setText(artist);

            ActionBar ab = getSupportActionBar();
            ab.setTitle(title);
            ab.setSubtitle(artist);

            view = (ImageView) findViewById(R.id.single_image);
            view.setImageBitmap(bmImg);


        pDialog.dismiss();


    }

Android-将Imageview设置为来自服务器的图像

2 个答案: