从网址获取多个图片

Question

我有一个应用程序允许下载3张图片并将它们显示到图库中 为了做到这一点，我使用了一个线程来下载图像和处理程序以便将图像进入画廊

的问题是图像不显示（imageviews是空的），到画廊（即使我看到3 imageview的我的3张图片）

我不知道这是因为连接非常慢（我在移动设备上开发），或者是因为在下载图像之前显示用户界面

非常感谢您的帮助

public class ChoiceLanguage extends Activity { 
    private TextView nomLangue; 

    private ArrayList<Language> listeLangues; 
    private ArrayList<String> listImages; 
    private Gallery gallery; 
    private String URL="******************"; 
    private Drawable mNoImage; 
    Bitmap bitmap; 
    ImageView imgView = null; 

    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.choice_language); 


     listeLangues= getIntent().getParcelableArrayListExtra("listeLangues"); 
     listImages=buildListImages(); 


     gallery = (Gallery) findViewById(R.id.galleryImg); 

     gallery.setAdapter(new AddImgAdp(this)); 

     gallery.setSpacing(10); 


     gallery.setOnItemClickListener(new OnItemClickListener() { 
      public void onItemClick(AdapterView parent, View v, int position, long id) {    

       System.out.println("URL "+ listImages.get(position)); 
      } 
     }); 


} 

    private InputStream openHttpConnection(String urlString) throws IOException { 
     InputStream in = null; 

     URL url = new URL(urlString); 
     URLConnection conn = url.openConnection(); 
     conn.connect(); 
     in=conn.getInputStream(); 
     return in; 
    } 

    private Bitmap downloadImage(ImageView iView, String url) { 
     Bitmap bitmap = null; 
     InputStream in = null; 
     BufferedInputStream bis ; 
     try { 

      in = openHttpConnection(url); 
      bis= new BufferedInputStream(in, 8192); 
      bitmap = BitmapFactory.decodeStream(bis); 
      bis.close(); 
      in.close(); 

     } catch (IOException e1) { 
      // TODO Auto-generated catch block 
      e1.printStackTrace(); 
     } 
     return bitmap; 

    } 


    private ArrayList<String> buildListImages() { 
     ArrayList<String> listImg = new ArrayList<String>(); 
     for(Language l : listeLangues) { 
      listImg.add(URL+l.getImagePath()); 

     } 

     return listImg; 
    } 

    public class AddImgAdp extends BaseAdapter { 
     int GalItemBg; 
     private Context cont; 

     public AddImgAdp(Context c) { 
      cont = c; 
      TypedArray typArray = obtainStyledAttributes(R.styleable.GalleryTheme); 
      GalItemBg = typArray.getResourceId(R.styleable.GalleryTheme_android_galleryItemBackground, 0); 
      typArray.recycle(); 
     } 

     public int getCount() { 
      return listImages.size(); 
     } 

     public Object getItem(int position) { 
      return position; 
     } 

     public long getItemId(int position) { 
      return position; 
     } 

     public View getView(final int position, View convertView, ViewGroup parent) { 

      if (convertView == null) { 
       imgView = new ImageView(cont); 
      } else { 
       imgView = (ImageView)convertView; 
      } 

      ThreadDownload progressDl= new ThreadDownload(position); 
      progressDl.start(); 

      imgView.setLayoutParams(new Gallery.LayoutParams(150, 150)); 
      imgView.setScaleType(ImageView.ScaleType.FIT_XY); 
      imgView.setBackgroundResource(GalItemBg); 

      return imgView; 
     } 
    } 
    private class SetImg extends Handler { 

     public void handleMessage(Message msg) { 

      imgView.setImageBitmap(bitmap); 
     } 
    } 
    private class ThreadDownload extends Thread { 
     SetImg img= new SetImg(); 
     int position ; 
     public ThreadDownload(int position) 
     { 
      super(); 
      this.position=position; 
     } 
     public void run() { 
     bitmap = downloadImage(imgView,listImages.get(position));  
     img.sendEmptyMessage(0); 
     } 
     } 



    } 

Answer 1

您可以使用SmartImageView的，它是一个下拉更换为Android标准的ImageView这还允许图像从网址或用户的联系人地址簿被加载。图像缓存到内存和磁盘以实现超快速加载。

https://github.com/loopj/android-smart-image-view