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下面是我的图像加载器代码，如果新图像名称不同，则工作正常，但如果新图像名称相同，则不会更改图像仅显示旧图像假设我有图像名称如果我在 url 中添加具有相同名称的新图像，myimage 将完美显示删除以前我的代码再次显示以前的图像由于缓存不显示新图像此代码中有什么问题请帮助我

private ImageLoader imgLoader;
private String strUrl = "http://solutionboat.com/work_2/asset/images/rifat.jpg";
private String strUrl1 = "http://solutionboat.com/work_2/asset/images/sobin.jpg";
private String strUrl2 = "http://solutionboat.com/work_2/asset/images/samol.jpg";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ImageView target0 = (ImageView) findViewById(R.id.target0);
    ImageView target1 = (ImageView) findViewById(R.id.target1);
    ImageView target2 = (ImageView) findViewById(R.id.target2);




    imgLoader = new ImageLoader(this);

    imgLoader.displayImage(strUrl, target0);
    imgLoader.displayImage(strUrl1, target1);
    imgLoader.displayImage(strUrl2, target2);


    ViewFlipper flipper = (ViewFlipper) findViewById(R.id.viewFlipper1);
    flipper.startFlipping();


}

}

ImageLoader 类

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);
}

final int stub_id = R.mipmap.ic_launcher;

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

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);

    Bitmap b = decodeFile(f);
    if(b != null)
        return b;

    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 (Throwable ex) {
        ex.printStackTrace();
        return null;
    }

}

private Bitmap decodeFile(File f) {
    try {
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f), null, o);

        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;
        }

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

    return null;
}

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;
    }

    @Override
    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;
}

class BitmapDisplayer implements Runnable {
    Bitmap bitmap;
    PhotoToLoad photoToLoad;

    public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
        bitmap = b;
        photoToLoad = p;
    }

    @Override
    public void run() {
        if(imageViewReused(photoToLoad))
            return;

        if(bitmap != null){
            photoToLoad.imageView.setImageBitmap(bitmap);
        } else {
            photoToLoad.imageView.setImageResource(stub_id);
        }
    }
}

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

}

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1 回答 1

0

使用 Picasso 解决任何图像加载/缓存问题。 http://square.github.io/picasso/

于 2015-08-19T18:56:55.493 回答