Android：将 ExternalStorageDirectory 替换为资产

Question

如何从 Assets 文件夹而不是 android.os.Environment.getExternalStorageDirectory()? 获取图像我需要根据我的要求替换此代码：

File directory = new File(
            android.os.Environment.getExternalStorageDirectory()
                    + File.separator + AppConstant.PHOTO_ALBUM);

谢谢

编辑：

ArrayList filePaths = new ArrayList();

if (directory.isDirectory()) {

        File[] listFiles = directory.listFiles();

        if (listFiles.length > 0) {

            for (int i = 0; i < listFiles.length; i++) {

                String filePath = listFiles[i].getAbsolutePath();

                if (IsSupportedFile(filePath)) {

                    filePaths.add(filePath);
                }
            }
        } else {
            Toast.makeText(
                    _context,
                    AppConstant.PHOTO_ALBUM
                            + " is empty. Please load some images in it !",
                    Toast.LENGTH_LONG).show();
        }

    } else {
        AlertDialog.Builder alert = new AlertDialog.Builder(_context);
        alert.setTitle("Error!");
        alert.setMessage(AppConstant.PHOTO_ALBUM
                + " directory path is not valid! Please set the image directory name AppConstant.java class");
        alert.setPositiveButton("OK", null);
        alert.show();
    }

Answer 1

这里是方法，如何获取已知资产子文件夹中的所有图像。您只需要知道资产中包含图像的子文件夹的名称。希望它会有所帮助。

private List<Bitmap> imageListFromAsset(String dirFrom) {
    //list of images in assets
    List<Bitmap> imageList = new ArrayList<Bitmap>();

    Resources res = getResources();
    AssetManager am = res.getAssets();
    String fileList[];
    try {
        fileList = am.list(dirFrom);

        for (String fileName : fileList) {
            imageList.add(getImageFromAsset(dirFrom+ File.separator +fileName, am));
        }

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

    return imageList;

}

private Bitmap getImageFromAsset(String path, AssetManager assetManager) {
    InputStream istr = null;
    try {
        istr = assetManager.open(path);
    } catch (IOException e) {
        e.printStackTrace();
    }
    Bitmap bitmap = BitmapFactory.decodeStream(istr);
    return bitmap;
}

如果您只需要这些图像的路径，请在fileList = am.list(dirFrom); 处停止。不要忘记在文件名之前添加 dirName。

根据评论中的要求进行编辑：

Resources res = getResources();
AssetManager am = res.getAssets();
String fileList[];
try {
    fileList = am.list(dirFrom);

    for (String fileName : fileList) {
        fileName = dirFrom + File.separator + fileName;
    }

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

现在您在 assets/dirName 中拥有所有文件路径。现在转换为 ArrayList；

List<String> imagePaths = new ArrayList<String>(Arrays.asList(fileList));

现在图像路径在列表中。