如何在 Android 通用图像加载器中保存图像？

Question

在Lazy-List 中，我使用此代码并将我的图像存储在名为LazyList 的文件夹中

ImageLoader imageLoader=new ImageLoader(context); imageLoader.DisplayImage(url, imageView);

但是在Universal-Image-Loader我用这个

 ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())    
            .build();
    ImageLoader.getInstance().init(config);
    img = (ImageView) this.findViewById(R.id.test_id);
    ImageLoader imageLoader = ImageLoader.getInstance();
    imageLoader.displayImage(URL.RECIPE_IMG_URL,img);

但每次它使用互联网获取图像并且没有将我的图像存储在任何文件夹中时，我也将.diskCache(new UnlimitedDiscCache(new File("myFolder"))) 添加到config 但myFolder 中没有任何内容。有什么想法吗？

Answer 1

你必须把图片保存在onLoadingComplete

试试这个，在onLoadingComplete 上，您必须将bitmap 保存到变量bitmap

imageLoader.getInstance().displayImage(imagePath, imageView, options, new SimpleImageLoadingListener() {
        @Override
        public void onLoadingStarted(String imageUri, View view) {
            spinner.setVisibility(View.VISIBLE);
        }

        @Override
        public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
            String message = null;
            switch (failReason.getType()) {
            case IO_ERROR:
                message = "Input/Output error";
                break;
            case DECODING_ERROR:
                message = "Image can't be decoded";
                break;
            case NETWORK_DENIED:
                message = "Downloads are denied";
                break;
            case OUT_OF_MEMORY:
                message = "Out Of Memory error";
                break;
            case UNKNOWN:
                message = "Unknown error";
                break;
            }


        }

        @Override
        public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {

            showedImgae = loadedImage;

        }
    });

现在点击保存按钮/如果你想将Bitmap/Image 保存到SDCard 使用这个

 public void downloadImage(){

    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/DCIM/youfoldername");    
    myDir.mkdirs();
    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);
    String fname = "imagename-"+ n +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ()) file.delete (); 
    try {
        FileOutputStream out = new FileOutputStream(file);
        showedImgae.compress(Bitmap.CompressFormat.JPEG, 100, out);
        Toast.makeText(MyActivity.this, "Image Saved", Toast.LENGTH_SHORT).show();
        out.flush();
        out.close();

    } catch (Exception e) {
        e.printStackTrace();
    }

    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    Uri contentUri = Uri.fromFile(file);
    mediaScanIntent.setData(contentUri);
    getApplicationContext().sendBroadcast(mediaScanIntent);
}

希望对你有帮助..

Answer 2

我找到了答案。默认情况下缓存是禁用的，我应该将DisplayImageOptions 添加到ImageLoaderConfiguration

这是代码

   DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
                .cacheInMemory(true)
                .cacheOnDisk(true)
                .build();

        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
                .defaultDisplayImageOptions(defaultOptions)
                .build();