1

我想从 url 下载图像并在线性布局的背景中设置，而不是在 android 的 imageview 中

在这里，我将我的代码用于从 url 下载图像，但现在我想在我的 LINER LAYOUT 背景中设置图像如何做到这一点

您可以在红色背景的图像中看到这是我想要设置此背景的布局背景动态从 url 加载

在此处输入图像描述

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();
    }

}
4

3 回答 3

3 
LinearLayout linearLayout=(LinearLayout)findViewById(R.id.yourLinearLayoutid);
        BitmapDrawable drawableBitmap=new BitmapDrawable(getBitmap(urlString));
        linearLayout.setBackgroundDrawable(drawableBitmap);

获取位图的方法：

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;
        }
    }

以上是有助于为您的布局设置背景的代码......

于 2013-01-04T09:53:01.450 回答
1

就个人而言，而不是将其传递ImageView给您的 ImageDownloader。我会创建一个界面。

interface ImageDownloadedCallback {
  void gotImage(Bitmap image);
}

然后将图像传递回活动中的回调。

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));
  }
});

这样，您可以在可以设置的内容上更加抽象。

于 2013-01-04T09:53:57.877 回答
-1 
public static void setImagebackground(View view,String url) {
        try {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
            URL x2 = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) x2.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            Drawable dr = new BitmapDrawable(myBitmap);
            view.setBackgroundDrawable(dr);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

用法

LinerLayout layout = findViewById(R.id.layout);
setimageview(layout,"https://link/to/image.png");
于 2020-12-05T14:30:15.867 回答