從url下載圖片並在Android中設置LinearLayout背景？

Question

我想從網址下載圖像，並設置在線性佈局中的背景不在圖像視圖中android

這裏我把我的代碼從url下載圖像下載，但現在我想設置圖像在我的LINER佈局背景如何爲此

你可以在紅色的背景圖片看到，是佈局的背景，我想設置這個研究背景從URL動態加載

RestaurantActivity.java

public class RestaurantActivity extends Activity implements OnClickListener { 

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

      int loader = R.drawable.loader; 

     Linearlayout middle =(Linearlayout)findviewbyid(R....); 

     ImageLoader imgLoader = new ImageLoader(getApplicationContext()); 
     String profileimageurl=spreferences.getString("image", ""); 
     imgLoader.DisplayImage(profileimageurl, loader, imageprofile); 

     } 

ImageLoader.java

public class ImageLoader { 

    MemoryCache memoryCache=new MemoryCache(); 
    FileCache fileCache; 
    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>()); 
    ExecutorService executorService; 

    public ImageLoader(Context context){ 
     fileCache=new FileCache(context); 
     executorService=Executors.newFixedThreadPool(5); 
    } 

    int stub_id = R.drawable.ic_launcher; 
    public void DisplayImage(String url, int loader, ImageView imageView) 
    { 
     stub_id = loader; 
     imageViews.put(imageView, url); 
     Bitmap bitmap=memoryCache.get(url); 
     if(bitmap!=null) 
      imageView.setImageBitmap(bitmap); 
     else 
     { 
      queuePhoto(url, imageView); 
      imageView.setImageResource(loader); 
     } 
    } 

    private void queuePhoto(String url, ImageView imageView) 
    { 
     PhotoToLoad p=new PhotoToLoad(url, imageView); 
     executorService.submit(new PhotosLoader(p)); 
    } 

    private Bitmap getBitmap(String url) 
    { 
     File f=fileCache.getFile(url); 

     //from SD cache 
     Bitmap b = decodeFile(f); 
     if(b!=null) 
      return b; 

     //from web 
     try { 
      Bitmap bitmap=null; 
      URL imageUrl = new URL(url); 
      HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection(); 
      conn.setConnectTimeout(30000); 
      conn.setReadTimeout(30000); 
      conn.setInstanceFollowRedirects(true); 
      InputStream is=conn.getInputStream(); 
      OutputStream os = new FileOutputStream(f); 
      Utils.CopyStream(is, os); 
      os.close(); 
      bitmap = decodeFile(f); 
      return bitmap; 
     } catch (Exception ex){ 
      ex.printStackTrace(); 
      return null; 
     } 
    } 

    //decodes image and scales it to reduce memory consumption 
    private Bitmap decodeFile(File f){ 
     try { 
      //decode image size 
      BitmapFactory.Options o = new BitmapFactory.Options(); 
      o.inJustDecodeBounds = true; 
      BitmapFactory.decodeStream(new FileInputStream(f),null,o); 

      //Find the correct scale value. It should be the power of 2. 
      final int REQUIRED_SIZE=70; 
      int width_tmp=o.outWidth, height_tmp=o.outHeight; 
      int scale=1; 
      while(true){ 
       if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE) 
        break; 
       width_tmp/=2; 
       height_tmp/=2; 
       scale*=2; 
      } 

      //decode with inSampleSize 
      BitmapFactory.Options o2 = new BitmapFactory.Options(); 
      o2.inSampleSize=scale; 
      return BitmapFactory.decodeStream(new FileInputStream(f), null, o2); 
     } catch (FileNotFoundException e) {} 
     return null; 
    } 

    //Task for the queue 
    private class PhotoToLoad 
    { 
     public String url; 
     public ImageView imageView; 
     public PhotoToLoad(String u, ImageView i){ 
      url=u; 
      imageView=i; 
     } 
    } 

    class PhotosLoader implements Runnable { 
     PhotoToLoad photoToLoad; 
     PhotosLoader(PhotoToLoad photoToLoad){ 
      this.photoToLoad=photoToLoad; 
     } 

     public void run() { 
      if(imageViewReused(photoToLoad)) 
       return; 
      Bitmap bmp=getBitmap(photoToLoad.url); 
      memoryCache.put(photoToLoad.url, bmp); 
      if(imageViewReused(photoToLoad)) 
       return; 
      BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad); 
      Activity a=(Activity)photoToLoad.imageView.getContext(); 
      a.runOnUiThread(bd); 
     } 
    } 

    boolean imageViewReused(PhotoToLoad photoToLoad){ 
     String tag=imageViews.get(photoToLoad.imageView); 
     if(tag==null || !tag.equals(photoToLoad.url)) 
      return true; 
     return false; 
    } 

    //Used to display bitmap in the UI thread 
    class BitmapDisplayer implements Runnable 
    { 
     Bitmap bitmap; 
     PhotoToLoad photoToLoad; 
     public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;} 
     public void run() 
     { 
      if(imageViewReused(photoToLoad)) 
       return; 
      if(bitmap!=null) 
       photoToLoad.imageView.setImageBitmap(bitmap); 
      else 
       photoToLoad.imageView.setImageResource(stub_id); 
     } 
    } 

    public void clearCache() { 
     memoryCache.clear(); 
     fileCache.clear(); 
    } 

} 

Answer 1

LinearLayout linearLayout=(LinearLayout)findViewById(R.id.yourLinearLayoutid); 
     BitmapDrawable drawableBitmap=new BitmapDrawable(getBitmap(urlString)); 
     linearLayout.setBackgroundDrawable(drawableBitmap); 

方法得到位圖：

private Bitmap getBitmap(String url) 
    { 


     //from web 
     try { 
      Bitmap bitmap=null; 
      URL imageUrl = new URL(url); 
      HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection(); 
      conn.setConnectTimeout(30000); 
      conn.setReadTimeout(30000); 
      conn.setInstanceFollowRedirects(true); 
      InputStream is=conn.getInputStream(); 
      OutputStream os = new FileOutputStream(f); 
      Utils.CopyStream(is, os); 
      os.close(); 
      bitmap = decodeFile(f); 
      return bitmap; 
     } catch (Exception ex){ 
      ex.printStackTrace(); 
      return null; 
     } 
    } 

以上是這有助於設定背景爲您佈局的代碼...

Answer 2

個人而言，不是將ImageView傳遞給ImageDownloader。我會創建一個接口。

interface ImageDownloadedCallback { 
    void gotImage(Bitmap image); 
} 

然後將圖像傳回給您的活動中的回調。

final Linearlayout middle =(Linearlayout)findviewbyid(R....); 

ImageLoader imgLoader = new ImageLoader(getApplicationContext()); 
String profileimageurl=spreferences.getString("image", ""); 
imgLoader.DisplayImage(profileimageurl, loader, new ImageDownloadedCallback(){ 
    void gotImage(Bitmap bm){ 
    middle.setBackgroundDrawable(new BitmapDrawable(bm)); 
    } 
}); 

這樣，你可以在你可以設置更多的抽象。